CBOR Object Signing and Encryption T. Reddy Internet-Draft Nokia Intended status: Standards Track H. Tschofenig Expires: 14 November 2026 UniBw M. F. Skokan Okta 13 May 2026 COSE HPKE PQ & PQ/T Algorithm Registrations draft-reddy-cose-hpke-pq-pqt-03 Abstract This document registers Post-Quantum (PQ) and Post-Quantum/ Traditional (PQ/T) hybrid algorithm identifiers for use with CBOR Object Signing and Encryption (COSE), building on the Hybrid Public Key Encryption (HPKE) framework. About This Document This note is to be removed before publishing as an RFC. The latest revision of this draft can be found at https://tireddy2.github.io/cose-hpke-pqt-pqc/draft-reddy-cose-hpke- pq-pqt.html. Status information for this document may be found at https://datatracker.ietf.org/doc/draft-reddy-cose-hpke-pq-pqt/. Discussion of this document takes place on the cose Working Group mailing list (mailto:cose@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/cose/. Subscribe at https://www.ietf.org/mailman/listinfo/cose/. Source for this draft and an issue tracker can be found at https://github.com/tireddy2/cose-hpke-pqt-pqc. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Reddy, et al. Expires 14 November 2026 [Page 1] Internet-Draft COSE HPKE PQ May 2026 Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 14 November 2026. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3 3. Algorithm Identifiers . . . . . . . . . . . . . . . . . . . . 3 3.1. PQ/T Hybrid Integrated Encryption Algorithms . . . . . . 4 3.2. Pure PQ Integrated Encryption Algorithms . . . . . . . . 4 3.3. PQ/T Hybrid Key Encryption Algorithms . . . . . . . . . . 5 3.4. Pure PQ Key Encryption Algorithms . . . . . . . . . . . . 5 4. COSE_Key Representation . . . . . . . . . . . . . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5.1. Security Strength . . . . . . . . . . . . . . . . . . . . 8 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 6.1. COSE Algorithms Registry . . . . . . . . . . . . . . . . 8 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 7.1. Normative References . . . . . . . . . . . . . . . . . . 13 7.2. Informative References . . . . . . . . . . . . . . . . . 13 Appendix A. Test Vectors . . . . . . . . . . . . . . . . . . . . 14 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 76 Document History . . . . . . . . . . . . . . . . . . . . . . . . 77 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 77 Reddy, et al. Expires 14 November 2026 [Page 2] Internet-Draft COSE HPKE PQ May 2026 1. Introduction [I-D.ietf-cose-hpke] defines how to use Hybrid Public Key Encryption (HPKE) with COSE_Encrypt0 and COSE_Encrypt structures ([RFC9052]) using traditional Key Encapsulation Mechanisms (KEM) based on Elliptic-curve Diffie-Hellman (ECDH). This document extends the set of registered HPKE algorithms to include Post-Quantum (PQ) and Post-Quantum/Traditional (PQ/T) hybrid KEMs, as defined in [I-D.ietf-hpke-pq]. These algorithms provide protection against attacks by cryptographically relevant quantum computers. The term "PQ/T hybrid" is used here consistent with [I-D.ietf-hpke-pq] to denote a combination of post-quantum and traditional algorithms, and should not be confused with HPKE's use of "hybrid" to describe the combination of asymmetric and symmetric encryption. 2. Conventions and Definitions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. This document uses the terms "Traditional Algorithm", "Post-Quantum Algorithm", "PQ/T Hybrid Scheme", and "PQ/T Hybrid KEM" as defined in [RFC9794]. The term "pure post-quantum" is used in this document to refer to a single-algorithm scheme using only a post-quantum algorithm, with no traditional component. 3. Algorithm Identifiers This section defines the algorithm identifiers for PQ and PQ/T HPKE- based encryption in COSE. Each algorithm is defined by a combination of an HPKE KEM, a Key Derivation Function (KDF), and an Authenticated Encryption with Associated Data (AEAD) algorithm. All algorithms defined in this section follow the same operational model as those in [I-D.ietf-cose-hpke], supporting both integrated encryption as defined in Section 3.2 of [I-D.ietf-cose-hpke] and key encryption as defined in Section 3.3 of [I-D.ietf-cose-hpke]. Test vectors for all algorithms defined in this section are provided in Appendix A. Reddy, et al. Expires 14 November 2026 [Page 3] Internet-Draft COSE HPKE PQ May 2026 3.1. PQ/T Hybrid Integrated Encryption Algorithms The following table lists the algorithm identifiers for PQ/T hybrid integrated encryption, where HPKE directly encrypts the plaintext without a separate Content Encryption Key: +=========+===========+=================+==========+=============+ | Name | Value | HPKE KEM | HPKE KDF | HPKE AEAD | +=========+===========+=================+==========+=============+ | HPKE-8 | TBD | MLKEM768-P256 | SHAKE256 | AES-256-GCM | | | (Assumed: | (0x0050) | (0x0011) | (0x0002) | | | 54) | | | | +---------+-----------+-----------------+----------+-------------+ | HPKE-9 | TBD | MLKEM768-X25519 | SHAKE256 | AES-256-GCM | | | (Assumed: | (0x647a) | (0x0011) | (0x0002) | | | 56) | | | | +---------+-----------+-----------------+----------+-------------+ | HPKE-10 | TBD | MLKEM1024-P384 | SHAKE256 | AES-256-GCM | | | (Assumed: | (0x0051) | (0x0011) | (0x0002) | | | 58) | | | | +---------+-----------+-----------------+----------+-------------+ Table 1: PQ/T Hybrid Integrated Encryption Algorithms These algorithms combine ML-KEM with a traditional elliptic curve algorithm in a PQ/T hybrid KEM, with the goal that compromise of either the post-quantum or the traditional component alone does not undermine the security of the resulting encryption. 3.2. Pure PQ Integrated Encryption Algorithms The following table lists the algorithm identifiers for pure post- quantum integrated encryption: +=========+===============+=============+==========+=============+ | Name | Value | HPKE KEM | HPKE KDF | HPKE AEAD | +=========+===============+=============+==========+=============+ | HPKE-11 | TBD (Assumed: | ML-KEM-512 | SHAKE256 | AES-128-GCM | | | 60) | (0x0040) | (0x0011) | (0x0001) | +---------+---------------+-------------+----------+-------------+ | HPKE-12 | TBD (Assumed: | ML-KEM-768 | SHAKE256 | AES-256-GCM | | | 62) | (0x0041) | (0x0011) | (0x0002) | +---------+---------------+-------------+----------+-------------+ | HPKE-13 | TBD (Assumed: | ML-KEM-1024 | SHAKE256 | AES-256-GCM | | | 64) | (0x0042) | (0x0011) | (0x0002) | +---------+---------------+-------------+----------+-------------+ Table 2: Pure PQ Integrated Encryption Algorithms Reddy, et al. Expires 14 November 2026 [Page 4] Internet-Draft COSE HPKE PQ May 2026 These algorithms provide pure post-quantum security using ML-KEM without a traditional algorithm component. 3.3. PQ/T Hybrid Key Encryption Algorithms The following table lists the algorithm identifiers for PQ/T hybrid key encryption, where HPKE encrypts the Content Encryption Key: +============+===========+=================+========+=============+ | Name | Value | HPKE KEM |HPKE KDF| HPKE AEAD | +============+===========+=================+========+=============+ | HPKE-8-KE | TBD | MLKEM768-P256 |SHAKE256| AES-256-GCM | | | (Assumed: | (0x0050) |(0x0011)| (0x0002) | | | 55) | | | | +------------+-----------+-----------------+--------+-------------+ | HPKE-9-KE | TBD | MLKEM768-X25519 |SHAKE256| AES-256-GCM | | | (Assumed: | (0x647a) |(0x0011)| (0x0002) | | | 57) | | | | +------------+-----------+-----------------+--------+-------------+ | HPKE-10-KE | TBD | MLKEM1024-P384 |SHAKE256| AES-256-GCM | | | (Assumed: | (0x0051) |(0x0011)| (0x0002) | | | 59) | | | | +------------+-----------+-----------------+--------+-------------+ Table 3: PQ/T Hybrid Key Encryption Algorithms These are the key encryption counterparts of the PQ/T hybrid integrated encryption algorithms defined in Table 1. 3.4. Pure PQ Key Encryption Algorithms The following table lists the algorithm identifiers for pure post- quantum key encryption: Reddy, et al. Expires 14 November 2026 [Page 5] Internet-Draft COSE HPKE PQ May 2026 +============+===============+=============+==========+=============+ | Name | Value | HPKE KEM | HPKE KDF | HPKE AEAD | +============+===============+=============+==========+=============+ | HPKE-11-KE | TBD | ML-KEM-512 | SHAKE256 | AES-128-GCM | | | (Assumed: | (0x0040) | (0x0011) | (0x0001) | | | 61) | | | | +------------+---------------+-------------+----------+-------------+ | HPKE-12-KE | TBD | ML-KEM-768 | SHAKE256 | AES-256-GCM | | | (Assumed: | (0x0041) | (0x0011) | (0x0002) | | | 63) | | | | +------------+---------------+-------------+----------+-------------+ | HPKE-13-KE | TBD | ML-KEM-1024 | SHAKE256 | AES-256-GCM | | | (Assumed: | (0x0042) | (0x0011) | (0x0002) | | | 65) | | | | +------------+---------------+-------------+----------+-------------+ Table 4: Pure PQ Key Encryption Algorithms These are the key encryption counterparts of the pure PQ integrated encryption algorithms defined in Table 2. 4. COSE_Key Representation Keys for the algorithms defined in this document use the "AKP" (Algorithm Key Pair) COSE key type defined in Section 3 of [I-D.ietf-cose-dilithium]. The required "alg" (label 3) parameter identifies the HPKE ciphersuite as well as whether the key is used for Integrated Encryption or Key Encryption. The public key parameter (label -1) contains the SerializePublicKey() output for the corresponding KEM, and for private keys the private key parameter (label -2) contains the SerializePrivateKey() output, both as defined in Section 4 of [I-D.ietf-hpke-hpke]. Both values are encoded as CBOR byte strings. Examples of COSE_Keys for each algorithm are provided in Appendix A. 5. Security Considerations The security considerations of [I-D.ietf-cose-hpke] and [I-D.ietf-hpke-pq] apply to this document. [I-D.ietf-pquip-pqc-engineers] provides general background on the threat posed by cryptographically relevant quantum computers (CRQCs), the properties of KEMs, and considerations for PQ/T hybrid schemes. This document registers ciphersuites based on ML-KEM-512. As noted in Section 3 of [I-D.ietf-hpke-pq], given the relative novelty of ML- KEM, there is concern that new cryptanalysis might reduce the Reddy, et al. Expires 14 November 2026 [Page 6] Internet-Draft COSE HPKE PQ May 2026 security level of ML-KEM-512. Use of ML-KEM-768 or ML-KEM-1024 acts as a hedge against such cryptanalysis at a modest performance penalty, and is RECOMMENDED where the additional overhead is acceptable. Unlike the companion JOSE algorithm registration document, this document retains ML-KEM-512-based ciphersuites for COSE. Discussion of this work identified COSE-specific deployment interest in these ciphersuites, including constrained environments and deployments that already support ML-KEM-512 in adjacent protocols and implementations. The ML-KEM-512 ciphersuites are therefore registered here to preserve that deployment option, while the stronger ML-KEM-768- and ML-KEM- 1024-based ciphersuites remain the preferred choice when their additional overhead is acceptable. The PQ/T hybrid ciphersuites registered by this document are motivated by the PQ/T Hybrid Confidentiality property (Section 5 of [RFC9794], Section 13.1 of [I-D.ietf-pquip-pqc-engineers]): confidentiality is preserved as long as at least one of the component algorithms remains secure. The traditional component protects against unforeseen cryptanalysis of ML-KEM, while the post-quantum component protects against Harvest Now, Decrypt Later (HNDL) attacks (Section 7 of [I-D.ietf-pquip-pqc-engineers]) by a future CRQC. PQ/T hybrid ciphersuites are generally preferred for this reason during the transition to post-quantum cryptography. The pure PQ ciphersuites are registered to accommodate deployments with regulatory or compliance mandates that require the exclusive use of post-quantum algorithms, such as those governed by the Commercial National Security Algorithm Suite 2.0 [CNSA2.0], as well as deployments where the size or performance overhead of a traditional component is undesirable. When the Key Encryption algorithms defined in Table 3 or Table 4 are used in a COSE_Encrypt structure with multiple COSE_Recipient entries, all recipients MUST use a quantum-resistant Key Management algorithm. Including a recipient that uses an algorithm that is not quantum-resistant would allow an adversary performing an HNDL attack to recover the Content Encryption Key once a CRQC becomes available; see Section 15.4 of [I-D.ietf-pquip-pqc-engineers]. Reddy, et al. Expires 14 November 2026 [Page 7] Internet-Draft COSE HPKE PQ May 2026 5.1. Security Strength Ciphersuites based on ML-KEM-512 target NIST post-quantum security level 1; those based on ML-KEM-768 target security level 3; and those based on ML-KEM-1024 target security level 5 (see Section 11 of [I-D.ietf-pquip-pqc-engineers]). In the PQ/T hybrid ciphersuites, the traditional component provides an additional classical security floor: P-256 and X25519 offer approximately 128-bit classical security, while P-384 offers approximately 192-bit classical security. The -KE variants share the same cryptographic properties as their integrated encryption counterparts. All ciphersuites use SHAKE256 as the KDF, aligning with the hash family used internally by ML-KEM. The AEAD is paired with the KEM security level: ML-KEM-512 ciphersuites use AES-128-GCM, while ML- KEM-768, ML-KEM-1024, and the PQ/T hybrid ciphersuites use AES- 256-GCM. As discussed in Section 3.1 of [I-D.ietf-pquip-pqc-engineers], symmetric primitives are only modestly affected by quantum attacks and doubling key sizes is not strictly required; AES-256-GCM is nonetheless selected for the higher-strength ciphersuites to provide a comfortable margin consistent with security level 3 and 5 parameter sets and with contemporary guidance such as [CNSA2.0]. AES-128-GCM is used with ML-KEM-512 since pairing a level-1 KEM with a level-5 AEAD would not improve the overall security level while increasing implementation and bandwidth cost. The widespread hardware acceleration and broad deployment of AES-GCM make it a reasonable choice for all ciphersuites defined in this document. 6. IANA Considerations 6.1. COSE Algorithms Registry This document requests registration of the following values in the IANA "COSE Algorithms" registry established by [RFC9053]: Note: The HPKE algorithm numbering is intentionally aligned with the companion JOSE document so that a given HPKE identifier denotes the same HPKE KEM, KDF, and AEAD combination across JOSE and COSE. 6.1.1. HPKE-8 * Name: HPKE-8 * Value: TBD (Assumed: 54) * Description: Integrated Encryption with HPKE using MLKEM768-P256 KEM, SHAKE256 KDF, and AES-256-GCM AEAD Reddy, et al. Expires 14 November 2026 [Page 8] Internet-Draft COSE HPKE PQ May 2026 * Capabilities: [kty] * Change Controller: IETF * Reference: Table 1 of this document * Recommended: Yes 6.1.2. HPKE-8-KE * Name: HPKE-8-KE * Value: TBD (Assumed: 55) * Description: Key Encryption with HPKE using MLKEM768-P256 KEM, SHAKE256 KDF, and AES-256-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 3 of this document * Recommended: Yes 6.1.3. HPKE-9 * Name: HPKE-9 * Value: TBD (Assumed: 56) * Description: Integrated Encryption with HPKE using MLKEM768-X25519 KEM, SHAKE256 KDF, and AES-256-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 1 of this document * Recommended: Yes 6.1.4. HPKE-9-KE * Name: HPKE-9-KE * Value: TBD (Assumed: 57) Reddy, et al. Expires 14 November 2026 [Page 9] Internet-Draft COSE HPKE PQ May 2026 * Description: Key Encryption with HPKE using MLKEM768-X25519 KEM, SHAKE256 KDF, and AES-256-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 3 of this document * Recommended: Yes 6.1.5. HPKE-10 * Name: HPKE-10 * Value: TBD (Assumed: 58) * Description: Integrated Encryption with HPKE using MLKEM1024-P384 KEM, SHAKE256 KDF, and AES-256-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 1 of this document * Recommended: Yes 6.1.6. HPKE-10-KE * Name: HPKE-10-KE * Value: TBD (Assumed: 59) * Description: Key Encryption with HPKE using MLKEM1024-P384 KEM, SHAKE256 KDF, and AES-256-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 3 of this document * Recommended: Yes Reddy, et al. Expires 14 November 2026 [Page 10] Internet-Draft COSE HPKE PQ May 2026 6.1.7. HPKE-11 * Name: HPKE-11 * Value: TBD (Assumed: 60) * Description: Integrated Encryption with HPKE using ML-KEM-512 KEM, SHAKE256 KDF, and AES-128-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 2 of this document * Recommended: Yes 6.1.8. HPKE-11-KE * Name: HPKE-11-KE * Value: TBD (Assumed: 61) * Description: Key Encryption with HPKE using ML-KEM-512 KEM, SHAKE256 KDF, and AES-128-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 4 of this document * Recommended: Yes 6.1.9. HPKE-12 * Name: HPKE-12 * Value: TBD (Assumed: 62) * Description: Integrated Encryption with HPKE using ML-KEM-768 KEM, SHAKE256 KDF, and AES-256-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 2 of this document Reddy, et al. Expires 14 November 2026 [Page 11] Internet-Draft COSE HPKE PQ May 2026 * Recommended: Yes 6.1.10. HPKE-12-KE * Name: HPKE-12-KE * Value: TBD (Assumed: 63) * Description: Key Encryption with HPKE using ML-KEM-768 KEM, SHAKE256 KDF, and AES-256-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 4 of this document * Recommended: Yes 6.1.11. HPKE-13 * Name: HPKE-13 * Value: TBD (Assumed: 64) * Description: Integrated Encryption with HPKE using ML-KEM-1024 KEM, SHAKE256 KDF, and AES-256-GCM AEAD * Capabilities: [kty] * Change Controller: IETF * Reference: Table 2 of this document * Recommended: Yes 6.1.12. HPKE-13-KE * Name: HPKE-13-KE * Value: TBD (Assumed: 65) * Description: Key Encryption with HPKE using ML-KEM-1024 KEM, SHAKE256 KDF, and AES-256-GCM AEAD * Capabilities: [kty] * Change Controller: IETF Reddy, et al. Expires 14 November 2026 [Page 12] Internet-Draft COSE HPKE PQ May 2026 * Reference: Table 4 of this document * Recommended: Yes 7. References 7.1. Normative References [I-D.ietf-cose-dilithium] Prorock, M. and O. Steele, "ML-DSA for JOSE and COSE", Work in Progress, Internet-Draft, draft-ietf-cose- dilithium-11, 15 November 2025, . [I-D.ietf-cose-hpke] Tschofenig, H., Jones, M. B., Steele, O., Daisuke, A., and L. Lundblade, "Use of Hybrid Public-Key Encryption (HPKE) with CBOR Object Signing and Encryption (COSE)", Work in Progress, Internet-Draft, draft-ietf-cose-hpke-25, 7 April 2026, . [I-D.ietf-hpke-hpke] Barnes, R., Bhargavan, K., Lipp, B., and C. A. Wood, "Hybrid Public Key Encryption", Work in Progress, Internet-Draft, draft-ietf-hpke-hpke-03, 2 March 2026, . [I-D.ietf-hpke-pq] Barnes, R. and D. Connolly, "Post-Quantum and Post- Quantum/Traditional Hybrid Algorithms for HPKE", Work in Progress, Internet-Draft, draft-ietf-hpke-pq-04, 2 March 2026, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 7.2. Informative References Reddy, et al. Expires 14 November 2026 [Page 13] Internet-Draft COSE HPKE PQ May 2026 [CNSA2.0] National Security Agency, "Announcing the Commercial National Security Algorithm Suite 2.0", May 2025, . [I-D.ietf-pquip-pqc-engineers] Banerjee, A., Reddy.K, T., Schoinianakis, D., Hollebeek, T., and M. Ounsworth, "Post-Quantum Cryptography for Engineers", Work in Progress, Internet-Draft, draft-ietf- pquip-pqc-engineers-14, 25 August 2025, . [RFC8792] Watsen, K., Auerswald, E., Farrel, A., and Q. Wu, "Handling Long Lines in Content of Internet-Drafts and RFCs", RFC 8792, DOI 10.17487/RFC8792, June 2020, . [RFC9052] Schaad, J., "CBOR Object Signing and Encryption (COSE): Structures and Process", STD 96, RFC 9052, DOI 10.17487/RFC9052, August 2022, . [RFC9053] Schaad, J., "CBOR Object Signing and Encryption (COSE): Initial Algorithms", RFC 9053, DOI 10.17487/RFC9053, August 2022, . [RFC9794] Driscoll, F., Parsons, M., and B. Hale, "Terminology for Post-Quantum Traditional Hybrid Schemes", RFC 9794, DOI 10.17487/RFC9794, June 2025, . Appendix A. Test Vectors This appendix provides test vectors for each algorithm defined in this document. For each algorithm, a private COSE_Key and an example encrypted COSE message (COSE_Encrypt0 for integrated encryption suites, or COSE_Encrypt with a single COSE_Recipient for key encryption suites) are provided, each shown in CBOR diagnostic notation and as hex-encoded CBOR. Long lines in the examples are folded using the single backslash strategy from [RFC8792]. Before using a folded example as a test vector, remove the RFC 8792 header and unfold the lines according to that strategy. The complete unfolded vector set is available as examples/cose-vectors.json in the repository (https://github.com/tireddy2/cose-hpke-pqt-pqc) for this document. Reddy, et al. Expires 14 November 2026 [Page 14] Internet-Draft COSE HPKE PQ May 2026 A.1. HPKE-8 NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'c3a85366a9abe1a96e7267131e8b8b11c5a4014b21809b28219c3\ df4818bf5dd', / alg / 3: 54 / HPKE-8 /, / pub / -1: h'e9746721ab42d4ab48ec36658fc2120f166fb6c15e04e3ca4044\ cc45161be39751d24c3a4c349bf143171c75a150175b101a1fe60bc825a7191b\ 87b11a4bb826ccac41c73d01547a61d8a1ee468f3508028a22b0f50002342316\ c76a75ef54550a91921683b069e8cd19978d24a4b88eaba53961501c6b5b5a19\ 7ae0767396464cc61a9d03e11e70438b8730a46c230cb57c5bf9cc545643b142\ 92a43b9a1f98468a1fbb63c8d67256cc6a8146459fa2bc8ceabd83a1823841b8\ 6b0181e80642ef6c8d5cb0c19d50b2ffb38c9f66c07a8b3c02f84791bb0bd21b\ 05163b2759c1bf218bcd3f3500732199969b2a8d7248878014c538ba88578914\ e134f2734cdca404625c64300ba555ab36138294fd319ea0425e6630394cf595\ 01088f1454389cd461d64a2d7f8387b47415a5a333032a48b485c053c2c8fe09\ 78add14a4df62ed7c30a9f28231273bd67b7b6718c23fe1ab1f8041d03aba540\ 170d4780c54823932e7301db618c5c654e3030a689ac59bdc869f6210a3491b8\ 4e46509a82b047da5b11b6a19ac9b55af51b47a904a8d60e13430cb1158d3374\ 41365b66d08aa8f1128c96946ae5171e59145d8d190a74287286e27679b048d3\ 9891b2e13a0305846c257a750a8d67482a75e5398a61028c558b36a62fb3405a\ c43826a12760e2b165ab752b67780b0f85134f890cf7b1cee6279dc68a31fffa\ 1cb531042263137fcb892363349ca4c8a5b5811e5a1f4dfba572a5578c5629af\ d1afb8a33f98495aa09c27dcc418ac534b73063e7f3cbd7eabc616d17eeb67c7\ 72970bed2554bbd296ee282200741fc179829cc433b31c0ba30564f261630d88\ 15da22283487aec1975cf3e23403508b8aa39037008b39b8123157a8f9652fce\ 6a1cb05394b52512d5c84d370a6330218ab87c4e60e72f28bc47ee6bcfa7a733\ 228bcfb2a41465d9680395aab7c535b034597eb8519548b8215a1399ebc1a5a1\ 182bf2737b770830e91129d3b9635b41e1321c00713ca0d51aad4118c7560352\ 29c8a25441043c8102647badb5788867a7187c20793219d1ca69a451036e4017\ e00686e182867465ab816861883a0f5f699d6bf04b3928a59e5866336061a866\ 4190a2b61350797e0111fbf00c61e565f471282821479ba280a609cb56760c42\ 312fee40bab6cab1b3ea4e7274acd84a4628c324e2074895c14dc6c554eac5c8\ 347003bcd9ad3724208d114a86634fb587215c75b3fed81c7163649b50c3eaa3\ 004cea1972c700bbc041a4a5305089085080b02a96b2e4a52c1632a90bd1cfa9\ 238d54c56eec6632b150bc5034cc7ad5a85e54a20deb688a89701461a922c71f\ d6273fad485b0f7a72c5523c0ea0ac74583635c4af2094682413b5d8a1ca4486\ 2773c39b802cc90542cd675466739b426e6716fe69a18343a203b1098f08bf7a\ 863cdbf8347a2c80af42b80e6072f32a960d9578e4a7c09d8401419bcaf33963\ d27a46a955aeb31ccfd66c3f0db867a7e67a4b222b1cd23dba71bb0db78385c9\ c10f6401a76b7a70d82f52808bccf45e40f632fdbc1513072b3d23b84a3506f2\ 686ec9b894e4d59d808443f79803d40a4d46865e24885f3fbc8cd6fb75642c5f\ 574c44bd449bdb90ce79b8a6ca9944befee7c5a9b685b9e545099ed34079c0fb\ 7da444f13d2404e1951deaeeb453d7ba1770be16a8f07e0ff160c937a0e71943\ e3f936bb0dc4ade1a3bc66b6948a55a8697ffd8ffe8d95cfc60573bb764bb8c0\ Reddy, et al. Expires 14 November 2026 [Page 15] Internet-Draft COSE HPKE PQ May 2026 c7d6d12d04296c', / priv / -2: h'7358a5d4227051d6a37809bc3cc64cab89b0d8f1fd676bd384b\ 907536310d740' } Figure 1: HPKE-8 COSE_Key (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 16] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 a50107025820c3a85366a9abe1a96e7267131e8b8b11c5a4014b21809b28219c3df4\ 818bf5dd031836205904e1e9746721ab42d4ab48ec36658fc2120f166fb6c15e04e3\ ca4044cc45161be39751d24c3a4c349bf143171c75a150175b101a1fe60bc825a719\ 1b87b11a4bb826ccac41c73d01547a61d8a1ee468f3508028a22b0f50002342316c7\ 6a75ef54550a91921683b069e8cd19978d24a4b88eaba53961501c6b5b5a197ae076\ 7396464cc61a9d03e11e70438b8730a46c230cb57c5bf9cc545643b14292a43b9a1f\ 98468a1fbb63c8d67256cc6a8146459fa2bc8ceabd83a1823841b86b0181e80642ef\ 6c8d5cb0c19d50b2ffb38c9f66c07a8b3c02f84791bb0bd21b05163b2759c1bf218b\ cd3f3500732199969b2a8d7248878014c538ba88578914e134f2734cdca404625c64\ 300ba555ab36138294fd319ea0425e6630394cf59501088f1454389cd461d64a2d7f\ 8387b47415a5a333032a48b485c053c2c8fe0978add14a4df62ed7c30a9f28231273\ bd67b7b6718c23fe1ab1f8041d03aba540170d4780c54823932e7301db618c5c654e\ 3030a689ac59bdc869f6210a3491b84e46509a82b047da5b11b6a19ac9b55af51b47\ a904a8d60e13430cb1158d337441365b66d08aa8f1128c96946ae5171e59145d8d19\ 0a74287286e27679b048d39891b2e13a0305846c257a750a8d67482a75e5398a6102\ 8c558b36a62fb3405ac43826a12760e2b165ab752b67780b0f85134f890cf7b1cee6\ 279dc68a31fffa1cb531042263137fcb892363349ca4c8a5b5811e5a1f4dfba572a5\ 578c5629afd1afb8a33f98495aa09c27dcc418ac534b73063e7f3cbd7eabc616d17e\ eb67c772970bed2554bbd296ee282200741fc179829cc433b31c0ba30564f261630d\ 8815da22283487aec1975cf3e23403508b8aa39037008b39b8123157a8f9652fce6a\ 1cb05394b52512d5c84d370a6330218ab87c4e60e72f28bc47ee6bcfa7a733228bcf\ b2a41465d9680395aab7c535b034597eb8519548b8215a1399ebc1a5a1182bf2737b\ 770830e91129d3b9635b41e1321c00713ca0d51aad4118c756035229c8a25441043c\ 8102647badb5788867a7187c20793219d1ca69a451036e4017e00686e182867465ab\ 816861883a0f5f699d6bf04b3928a59e5866336061a8664190a2b61350797e0111fb\ f00c61e565f471282821479ba280a609cb56760c42312fee40bab6cab1b3ea4e7274\ acd84a4628c324e2074895c14dc6c554eac5c8347003bcd9ad3724208d114a86634f\ b587215c75b3fed81c7163649b50c3eaa3004cea1972c700bbc041a4a53050890850\ 80b02a96b2e4a52c1632a90bd1cfa9238d54c56eec6632b150bc5034cc7ad5a85e54\ a20deb688a89701461a922c71fd6273fad485b0f7a72c5523c0ea0ac74583635c4af\ 2094682413b5d8a1ca44862773c39b802cc90542cd675466739b426e6716fe69a183\ 43a203b1098f08bf7a863cdbf8347a2c80af42b80e6072f32a960d9578e4a7c09d84\ 01419bcaf33963d27a46a955aeb31ccfd66c3f0db867a7e67a4b222b1cd23dba71bb\ 0db78385c9c10f6401a76b7a70d82f52808bccf45e40f632fdbc1513072b3d23b84a\ 3506f2686ec9b894e4d59d808443f79803d40a4d46865e24885f3fbc8cd6fb75642c\ 5f574c44bd449bdb90ce79b8a6ca9944befee7c5a9b685b9e545099ed34079c0fb7d\ a444f13d2404e1951deaeeb453d7ba1770be16a8f07e0ff160c937a0e71943e3f936\ bb0dc4ade1a3bc66b6948a55a8697ffd8ffe8d95cfc60573bb764bb8c0c7d6d12d04\ 296c2158207358a5d4227051d6a37809bc3cc64cab89b0d8f1fd676bd384b9075363\ 10d740 Figure 2: HPKE-8 COSE_Key (Hex-Encoded CBOR) Reddy, et al. Expires 14 November 2026 [Page 17] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt0 / 16([ / protected / h'a1011836', / unprotected / { / kid / 4: h'c3a85366a9abe1a96e7267131e8b8b11c5a4014b21809b28219\ c3df4818bf5dd', / ek / -4: h'ee2bfd015fc29cab76d7024754154e789bb7b17ab53d4c25514\ b44d5dd2a1215b5e5d5b605cea67cdfa55c038461478cddfa3a7e0b5d3252941\ 5363a37fa81c734da29fe657c8a33b2ced5f7d773a30c9a5d8feec7b9d57f1b0\ 8c541db82014c5f57e917868f7d72817fc9add137a9e06c2570ebc92e3ecb017\ 288e335a5d7445b2e37ba9355c40d355210c25c463873d11f65f0eabc11b8def\ f6aceb3ccc4b0cd76980cb4903d2783e6728582102e88f2503d2fb94eaab2b9c\ 9577d57c029b623e5605125adf6764254a3fb9d32efd08bf4686f78a68a29f0a\ c9b5ef55d562b6e9413ba6a8f88265a8f8e70aef5cf55743c226b3d4ca0f00d7\ 0e8bd40d92af6fbb5eed0303f2a7a3d2328e13664929a05cc8e1922950b59fed\ 47273834271b8a9bb40be86f9b8c108d184b06f9d085ecc2201f82c4ee8e6ee1\ bc7711c53fcda8ea0c722f072ca2755ff981555be2f115d6c3cd5ddd94d2f74f\ cfe7db1f7818f3abdef0efa8eb2e906258b9e5718be3ea91d27d976c979ae387\ 65bf7957219ed7c70ac7cebda19cd7ca4e6b0cd4dae631fb5a34283463441456\ 695e5bc705fe3cac8ed36b24c4e131b30c06505a941a01788fcd7ee60af2be6f\ 3ca7e497d5bd2fd82e873d3d47fdba7c95b5b2caf23c53ef74a08b096137ebcb\ a2acb9063be623c5c46c9094eb95144375d34f3ffc514c241e022006f5c089ed\ e2f5cc94bfe98542b6a3e5e5c2d7e3af973c040b035ea8edd100678f4c509a82\ 3c68501f2e6accfb5d52fbf1962d4b9c83dfbb94562c5effa6e83344d63e28fb\ 9ade840ed2b7c7e3ddaa22199c8bd2bd352c60ea30fe4494d78fb0055e365f1c\ 703f0b8cd77efebf9ebd7c46e4f9456ba5c1745f53d9415f8a17ee4cc991df07\ a29bf57c1d5aec0991ffede13a866746a071f62279c4ccc1d8385f9b5bb159cf\ 0d435e80752dfce233f3ad5638c54deae75abcab036a5fcecb7406acab1b9e82\ 613cd508c5b21a72c21173c7d97d76c2a3b7126599287965a512772782c75cee\ 09351e6e821e7f115f8c30d5dfb6bd119e9259cd934d7fc01dc6c5249f093bdd\ b2e2d086d4bde681faa0d262e637025bf4c6152d39587bd4d1e11fae3cfabf47\ 59b30d7ab84b29d58c7b5ff57f7cff98f21e42592f5dc23b484422c25fa26a37\ 816b2f9faad88dedfb7b75167c1990b6db8bff4af3200438f28e4da5196abe95\ 6e4e86d58ffe6f3e350f424cb91f0070c305c862c659d12a083123a6cc01ad8b\ c1c2decd2aebb1385733e596ae27601cfea9b85c884fadc06bc42c18b0b8d294\ 7330677dbb556ce7f761076af565e07e85b42ef2e248b77efd4cb8ee7c9366a1\ 88885488ee13eb20cad292d000e5a9cc6ab0e471888ae7817c40b17070a2767e\ 24497c2a2f5ccfafa4c1089447968da5a55cb82bc1218efdf110658f9e1900c1\ 3b8ac6cd9cf857c66e69893a750ffb227f461e1ce33f8fbbe18da70eab47be43\ 2f0067033f0c138ec5344a71b2edf52685f83e38650e46aee2533d14bf040f6e\ b93cee870ddc4044692891949e447dcbd484a73658296de85b8cbc3c3bfd3e2b\ e23dabf61d9261a7f2af6d0a518d7a8d94c5d8bf1522e35d4ecdcb2828bced22\ 7eef3c62b683dcd' }, / ciphertext / h'3a8c6eca287e2c95d2b50b8a8cb47533d8fd937f714d3750d\ a6bdcec965e1c5a87c8a5bbc6d5713a75998f63c19756f3b70f1bab9ec905c6c\ 46654725310cffc9361b0a3edb1f792ee5e900b945cbaed4b91911de4809cd2a\ Reddy, et al. Expires 14 November 2026 [Page 18] Internet-Draft COSE HPKE PQ May 2026 5efeb2600e581b3fd53e25af1bd89dab7ff74cdf5fd8ebad8c3154df2067548b\ edab590abde33880787d17e70553e253f448844257edf5d8a982671ad045ee20\ e043f8c11ba554b0b743e06a1f1783d1f646f0d620d0d0e1532f728fd033761d\ 37b80229952995054a75aa13b60dc84c91cf30d8905366099629d2c3998b35af\ cbef29789d1b5d1372f97b1cba338805e1ab7b9d188553890bad36b57370261a\ 7f3ef5d3cc9a6abf272e7ff73e01a4f460535e8f995f282ef8de34a8666645d9\ 307d7c19b28b57df9' ]) Figure 3: HPKE-8 COSE_Encrypt0 (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 19] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 d08344a1011836a2045820c3a85366a9abe1a96e7267131e8b8b11c5a4014b21809b\ 28219c3df4818bf5dd23590481ee2bfd015fc29cab76d7024754154e789bb7b17ab5\ 3d4c25514b44d5dd2a1215b5e5d5b605cea67cdfa55c038461478cddfa3a7e0b5d32\ 529415363a37fa81c734da29fe657c8a33b2ced5f7d773a30c9a5d8feec7b9d57f1b\ 08c541db82014c5f57e917868f7d72817fc9add137a9e06c2570ebc92e3ecb017288\ e335a5d7445b2e37ba9355c40d355210c25c463873d11f65f0eabc11b8deff6aceb3\ ccc4b0cd76980cb4903d2783e6728582102e88f2503d2fb94eaab2b9c9577d57c029\ b623e5605125adf6764254a3fb9d32efd08bf4686f78a68a29f0ac9b5ef55d562b6e\ 9413ba6a8f88265a8f8e70aef5cf55743c226b3d4ca0f00d70e8bd40d92af6fbb5ee\ d0303f2a7a3d2328e13664929a05cc8e1922950b59fed47273834271b8a9bb40be86\ f9b8c108d184b06f9d085ecc2201f82c4ee8e6ee1bc7711c53fcda8ea0c722f072ca\ 2755ff981555be2f115d6c3cd5ddd94d2f74fcfe7db1f7818f3abdef0efa8eb2e906\ 258b9e5718be3ea91d27d976c979ae38765bf7957219ed7c70ac7cebda19cd7ca4e6\ b0cd4dae631fb5a34283463441456695e5bc705fe3cac8ed36b24c4e131b30c06505\ a941a01788fcd7ee60af2be6f3ca7e497d5bd2fd82e873d3d47fdba7c95b5b2caf23\ c53ef74a08b096137ebcba2acb9063be623c5c46c9094eb95144375d34f3ffc514c2\ 41e022006f5c089ede2f5cc94bfe98542b6a3e5e5c2d7e3af973c040b035ea8edd10\ 0678f4c509a823c68501f2e6accfb5d52fbf1962d4b9c83dfbb94562c5effa6e8334\ 4d63e28fb9ade840ed2b7c7e3ddaa22199c8bd2bd352c60ea30fe4494d78fb0055e3\ 65f1c703f0b8cd77efebf9ebd7c46e4f9456ba5c1745f53d9415f8a17ee4cc991df0\ 7a29bf57c1d5aec0991ffede13a866746a071f62279c4ccc1d8385f9b5bb159cf0d4\ 35e80752dfce233f3ad5638c54deae75abcab036a5fcecb7406acab1b9e82613cd50\ 8c5b21a72c21173c7d97d76c2a3b7126599287965a512772782c75cee09351e6e821\ e7f115f8c30d5dfb6bd119e9259cd934d7fc01dc6c5249f093bddb2e2d086d4bde68\ 1faa0d262e637025bf4c6152d39587bd4d1e11fae3cfabf4759b30d7ab84b29d58c7\ b5ff57f7cff98f21e42592f5dc23b484422c25fa26a37816b2f9faad88dedfb7b751\ 67c1990b6db8bff4af3200438f28e4da5196abe956e4e86d58ffe6f3e350f424cb91\ f0070c305c862c659d12a083123a6cc01ad8bc1c2decd2aebb1385733e596ae27601\ cfea9b85c884fadc06bc42c18b0b8d2947330677dbb556ce7f761076af565e07e85b\ 42ef2e248b77efd4cb8ee7c9366a188885488ee13eb20cad292d000e5a9cc6ab0e47\ 1888ae7817c40b17070a2767e24497c2a2f5ccfafa4c1089447968da5a55cb82bc12\ 18efdf110658f9e1900c13b8ac6cd9cf857c66e69893a750ffb227f461e1ce33f8fb\ be18da70eab47be432f0067033f0c138ec5344a71b2edf52685f83e38650e46aee25\ 33d14bf040f6eb93cee870ddc4044692891949e447dcbd484a73658296de85b8cbc3\ c3bfd3e2be23dabf61d9261a7f2af6d0a518d7a8d94c5d8bf1522e35d4ecdcb2828b\ ced227eef3c62b683dcd5901213a8c6eca287e2c95d2b50b8a8cb47533d8fd937f71\ 4d3750da6bdcec965e1c5a87c8a5bbc6d5713a75998f63c19756f3b70f1bab9ec905\ c6c46654725310cffc9361b0a3edb1f792ee5e900b945cbaed4b91911de4809cd2a5\ efeb2600e581b3fd53e25af1bd89dab7ff74cdf5fd8ebad8c3154df2067548bedab5\ 90abde33880787d17e70553e253f448844257edf5d8a982671ad045ee20e043f8c11\ ba554b0b743e06a1f1783d1f646f0d620d0d0e1532f728fd033761d37b8022995299\ 5054a75aa13b60dc84c91cf30d8905366099629d2c3998b35afcbef29789d1b5d137\ 2f97b1cba338805e1ab7b9d188553890bad36b57370261a7f3ef5d3cc9a6abf272e7\ ff73e01a4f460535e8f995f282ef8de34a8666645d9307d7c19b28b57df9 Figure 4: HPKE-8 COSE_Encrypt0 (Hex-Encoded CBOR) Reddy, et al. Expires 14 November 2026 [Page 20] Internet-Draft COSE HPKE PQ May 2026 A.2. HPKE-8-KE NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'cb289275c0c25add86b439534a99efaade738327a2232af712189\ 01e2ae2892c', / alg / 3: 55 / HPKE-8-KE /, / pub / -1: h'a714115eb4492e47bc04c0576b5153ef880cf5fabbd5f13044f4\ 67755b26b1800c53a96512725a78a01a823c64e38ca5f4fb27ed8067ded5575c\ b56ba88c725a11ac3f6a661f86367a880169130605f432f9333f47374513e84a\ 2c7a873e6a8ffcf6444b6b3a3bdb4192f93b0fa7ca64a8810d22abbd682b2822\ 28d4371c81f1c46b2c42b5ec75c35663570788656b5503757f25d8a3ce86c689\ 2534773ab28d504109055c5a24852cbb97eab16d88fa6c6b74a56afa4a1da453\ 219c7fe687023b52c100aab88f07b0e23c67851ba35f855c68e1363104371549\ 93e9480ca5649fca624d04eab0377b94dc43bf92d80c3f075fad1562852822ae\ 4895ec18525bdb8df793938a088922279dc4f57a6ac2b6edc09c3e137494940e\ ca795a87c063c9260ac1d3111f2c555611839a7277eaf793103a1ba0186ae620\ 2472ac1e77b3be2b00b4f577157227a0abeb5823635630e90175713f5b6aafbc\ f224269398b4a033b6951cc610413e2b5119071dcfec03e278a4d83164f36b1f\ 0cda42fe557f5d6611dca5708818b1dad081dedc3e8fd96813701ac4679fb329\ 743cf42c146bb68b9aaeb4195472545484c524886732127c794b4c4d633cae33\ e9406b75a937394473f4a8aa62afa1b669d298be131627a48409ee73c914d5c9\ f6283792fa4d0b19ca944c2c3f9c3dd526ce70b381439748abe9a887890af590\ abcbf264026980c61bbd9060ae82169c08f694aa066b8a03bd6d01c7c348225f\ 6101e6103eafa571cccc1825ca31f52c43d2d255b003210941a11ae4b9c2876b\ 3e16b2facb3bf003198979b70f79837beb00d155512da3771e0999c3e92e77cb\ 2eedb2a1f7361e7388876b2810ab6c921a878e2a819eb152bbedf88b9566982c\ db6a126cb005b95096465b3885267159ac4f0775c991beacf2246bf789f60004\ e137b85e0131a286892382c075a89fd6cb46fa511917c4663659af9b8c1d00c6\ 5002a3cf2e23b0915021b213147dabcc79588679d824e7bcb724da60a90b97fa\ c108e4d98d3055b8ef047701eb02a6ebaafd292a8fc11d79659a23087e2fc883\ 60273b37eb4b84dc2024ea67236a47f82a6055286280a8ba6eb22307840457e2\ 6d47328567f645d3033d1984cdb0133b7579713d45158cb0b258559849c45dc0\ 7ca91ff75ecaf6848e7cbed038293ae479a71056b45184b2801024198f645ba6\ c1807975993205126b40f50434c370d1e67fd72aa5d681487534024201259fd0\ 457c23c1e8c097f246649cfa2f8499aaef80402cf59a20d799867888e3c1467f\ cb73f15749d7532eeeac6b362507340a5331c91edc0c36a8a97e36d15e47c3ae\ e9fa901f47764a157e1af09cbb18ca7d474d535cb9cd8865bba659c2f919dfd8\ ca97eb7b132c3aac012751f580da11175cc683a8155162fab08623349dba0e0e\ 15942545bc384a41a7d788dde7a5eed44556289943b2ac66650157255f18942f\ 87b0cce75540bd45128bfc4f433b33fbec962770c5998585e9e31093b15d517b\ bb1e617131fb8d3461ccca9c7c4bd46a7c2888f4e7ce7aac1549a6b630077e6f\ 67200c0a3ca9578219c31553d151c2b52c7157a5b5c248e36b1989aa1714f525\ c802a77326a367a81984535ec480d68920a9e0be789ccf78f0bf8a7281676701\ ecb9e023889c04f5d732ea452dc90eafd3f3b159bf0eb8cd38bbde86b4e95df3\ 0548701ed01367ddee0f574c2752860a5d98c80d9c62ab24cd00d916ed9a79fe\ Reddy, et al. Expires 14 November 2026 [Page 21] Internet-Draft COSE HPKE PQ May 2026 81dc466f202b24', / priv / -2: h'6e250ae4da89cd7cd6100374176cf392b12bf51a7f417e798ac\ fe3ed562e1c24' } Figure 5: HPKE-8-KE COSE_Key (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 22] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 a50107025820cb289275c0c25add86b439534a99efaade738327a2232af71218901e\ 2ae2892c031837205904e1a714115eb4492e47bc04c0576b5153ef880cf5fabbd5f1\ 3044f467755b26b1800c53a96512725a78a01a823c64e38ca5f4fb27ed8067ded557\ 5cb56ba88c725a11ac3f6a661f86367a880169130605f432f9333f47374513e84a2c\ 7a873e6a8ffcf6444b6b3a3bdb4192f93b0fa7ca64a8810d22abbd682b282228d437\ 1c81f1c46b2c42b5ec75c35663570788656b5503757f25d8a3ce86c6892534773ab2\ 8d504109055c5a24852cbb97eab16d88fa6c6b74a56afa4a1da453219c7fe687023b\ 52c100aab88f07b0e23c67851ba35f855c68e136310437154993e9480ca5649fca62\ 4d04eab0377b94dc43bf92d80c3f075fad1562852822ae4895ec18525bdb8df79393\ 8a088922279dc4f57a6ac2b6edc09c3e137494940eca795a87c063c9260ac1d3111f\ 2c555611839a7277eaf793103a1ba0186ae6202472ac1e77b3be2b00b4f577157227\ a0abeb5823635630e90175713f5b6aafbcf224269398b4a033b6951cc610413e2b51\ 19071dcfec03e278a4d83164f36b1f0cda42fe557f5d6611dca5708818b1dad081de\ dc3e8fd96813701ac4679fb329743cf42c146bb68b9aaeb4195472545484c5248867\ 32127c794b4c4d633cae33e9406b75a937394473f4a8aa62afa1b669d298be131627\ a48409ee73c914d5c9f6283792fa4d0b19ca944c2c3f9c3dd526ce70b381439748ab\ e9a887890af590abcbf264026980c61bbd9060ae82169c08f694aa066b8a03bd6d01\ c7c348225f6101e6103eafa571cccc1825ca31f52c43d2d255b003210941a11ae4b9\ c2876b3e16b2facb3bf003198979b70f79837beb00d155512da3771e0999c3e92e77\ cb2eedb2a1f7361e7388876b2810ab6c921a878e2a819eb152bbedf88b9566982cdb\ 6a126cb005b95096465b3885267159ac4f0775c991beacf2246bf789f60004e137b8\ 5e0131a286892382c075a89fd6cb46fa511917c4663659af9b8c1d00c65002a3cf2e\ 23b0915021b213147dabcc79588679d824e7bcb724da60a90b97fac108e4d98d3055\ b8ef047701eb02a6ebaafd292a8fc11d79659a23087e2fc88360273b37eb4b84dc20\ 24ea67236a47f82a6055286280a8ba6eb22307840457e26d47328567f645d3033d19\ 84cdb0133b7579713d45158cb0b258559849c45dc07ca91ff75ecaf6848e7cbed038\ 293ae479a71056b45184b2801024198f645ba6c1807975993205126b40f50434c370\ d1e67fd72aa5d681487534024201259fd0457c23c1e8c097f246649cfa2f8499aaef\ 80402cf59a20d799867888e3c1467fcb73f15749d7532eeeac6b362507340a5331c9\ 1edc0c36a8a97e36d15e47c3aee9fa901f47764a157e1af09cbb18ca7d474d535cb9\ cd8865bba659c2f919dfd8ca97eb7b132c3aac012751f580da11175cc683a8155162\ fab08623349dba0e0e15942545bc384a41a7d788dde7a5eed44556289943b2ac6665\ 0157255f18942f87b0cce75540bd45128bfc4f433b33fbec962770c5998585e9e310\ 93b15d517bbb1e617131fb8d3461ccca9c7c4bd46a7c2888f4e7ce7aac1549a6b630\ 077e6f67200c0a3ca9578219c31553d151c2b52c7157a5b5c248e36b1989aa1714f5\ 25c802a77326a367a81984535ec480d68920a9e0be789ccf78f0bf8a7281676701ec\ b9e023889c04f5d732ea452dc90eafd3f3b159bf0eb8cd38bbde86b4e95df3054870\ 1ed01367ddee0f574c2752860a5d98c80d9c62ab24cd00d916ed9a79fe81dc466f20\ 2b242158206e250ae4da89cd7cd6100374176cf392b12bf51a7f417e798acfe3ed56\ 2e1c24 Figure 6: HPKE-8-KE COSE_Key (Hex-Encoded CBOR) Reddy, et al. Expires 14 November 2026 [Page 23] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt / 96([ / protected / h'a10103', / unprotected / { / iv / 5: h'd3c087cd66a26bc98bdc0348' }, / ciphertext / h'dbf6e759e253d416e9a0cd054dc13184bffefe2a20750c3e4\ e42a1380a571e4662a8145601c4f4fb97291394f5982394d2cbc3f67d2ea6326\ 4e96c788c4380d02bd7fdd7a5966f7c22ce65cb3ffc632dc0bad0cf300ee2d6f\ 979ec4dca06abd444706e826ac1986abae784e5bb070cb5a22d43660707a2035\ afbde9a0d6c8759028fb81c569ed84666bf97b07b56356df22fa4098042ec174\ fc3d2c93801ef0ca3801983f4dd209077ff70406a633c97a7b2a9f8133c906d2\ 239c64ea74a2180b4de0c32c9b2259cc45f144142919e0e6bc8b13953866a189\ 270fb7c9b2963ab72a9a9735747ed904c0ce0117de98edcf74b989c87d6b2f38\ 44be46756bf6b94c0a34a6418c82e2e76d8ca6a97fde52bfbecd37420dcebea2\ 7b81d81779750ce58', / recipients / [ [ / protected / h'a2011837045820cb289275c0c25add86b439534a99efaa\ de738327a2232af71218901e2ae2892c', / unprotected / { / ek / -4: h'c2e3fbb37cc85019bc7369ea564d7b4bd33ae1a4c0323d8\ b6416951d25b370c49daa5c4075ddfb0decdd1289e6d239106ebb106e6ae9871\ 9e9dd43549cf54233cf901beacb315702d8a4efde1fc5350e19172a103390e9c\ 5b6c131b5402f9b43efcbe2864a98ed40b534df3cc72803c37e89b9dc9f6ac4e\ 3bc219913f6aa49a10fd587ca737284061daed1dc9ded416799f5d0e9483639d\ 8139dfc05813df276a5fbd3b657d37c2d64774d912982e7854eac3983c284822\ 78fa6f819e3f00cd0f113826f1df92eb7164a1bc9961354cb761a491a27499fb\ b1a9603d1c07b434c772dcccfa2e6a80b9a452eaff50ff23cada98b065003d74\ f6f5d0bad46893f9d94d5e308f65b848b4fb726a15099123c9e1b918f0a74e77\ 03bd746c2f8e7f5f3d5a4c475469ea2bf37dff5cb3a0b5596b24eb278b5ef849\ c4143b3429ea6d463eb5a17267e81830e60f11e4803663d07ce029ffe9448980\ ef0daacc3159194251279591d316c7fc10bb853aafbfe6b6f75d3569855113d5\ 7aa8ecc911e2023fb49e2b8643e00a30bd6c69588eeb19dffacac80d140df33b\ f09cf16babf76e8d6d82341fecabe76259296b644ee001e10a6f33d4d6cda0bf\ db742b1c7d33c702563b3d32dec2807610c0b09c07a9fea3002bd4be5c511f18\ 5afbeea7ee11175b70a345ec48658372fb8e79cccc14c47b541dcdbce012ee3e\ 4b3f0f3a01576e34edd5d6e2f4f8b49a7f3f7e831643e6b8b11ce4a4e9b66bdf\ b9664b5ca5fac6f0089f51cccb4ca076afa0540d089da1486caa3228245e2d0f\ cb22cd3b4943a0ea4040b283504dd34b2b85453749613e6659f2c91a7652115c\ 4886e7e2030d08edf85db93ae1befe326da6ed92f4c4ac2ea1ce6d5030cfc909\ a6e821c8d4514d658555e40dd5efa57b6d1c05e85db6284fdbcb778c4d8e09ee\ a446aa046174e0877998a830974a51b4aee52c896a9f3ee1b5c3bcac9bf4663c\ a5d100b2bf96daaef9e411297c65a66f4819c95298e05fad7991ceba212d8437\ 9475012e925856ad8d8933f09178428321507e99f00c0fd85ad8a73b27a4b48a\ 0a9c37752fd6ae03d270d173e43720f26a6e5d004108d8ba5652a5ffb0c0af89\ 5af218481f6a3fb0212c7f530dd39950ff945600e29e917314af5378cd175e26\ Reddy, et al. Expires 14 November 2026 [Page 24] Internet-Draft COSE HPKE PQ May 2026 9d9b49c53963fdb31e1553eed7008e842375fed0cb377e2fc1d1de540a6fcbf1\ d324c9f1f04bd42084b6c9f5ac30bde6f7e3a334999b7003a388ac1604fa651e\ 77daba71457e00d0c528b036d1947ab5bb4c0ce2a29ee37f62690b96c655285a\ 70604881a10ba8bad19ec171fa73be914d0571dbf1e6f01fc8a8b83499a6f507\ 905f6027bdffdbdee06259de85fe11f68a4c414f6c7348f1ec11f1d9777e4c56\ 2b964964359842773f29f0091e953dadbed437c8d35351bf12ec8f91cdde59bf\ d10f4bb63153039c8baa683102cb90a29029f691a33c274b4391887a036be6a7\ 7e3c9f894f0573ffa5d8c6de1ab01e4af0b428f4bc371d0d5f7af6d40b108fca\ 27431c7bf2a40dae8049a3aceb56d5773f08016039d6d0370b5a081a1a0f2299\ 8330af2fe1643860546847bee9d67c56747da91b42d60c1a4f1686669e34683f\ 24ffceda910176902f7' }, / ciphertext / h'a520aac9e94fe8d7b006488182d6da449ea6d62714155\ 3f613070a6498b2ca27a87f50e20c8f30d621fd20fa83187c28' ] ] ]) Figure 7: HPKE-8-KE COSE_Encrypt (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 d8608443a10103a1054cd3c087cd66a26bc98bdc0348590121dbf6e759e253d416e9\ a0cd054dc13184bffefe2a20750c3e4e42a1380a571e4662a8145601c4f4fb972913\ 94f5982394d2cbc3f67d2ea63264e96c788c4380d02bd7fdd7a5966f7c22ce65cb3f\ fc632dc0bad0cf300ee2d6f979ec4dca06abd444706e826ac1986abae784e5bb070c\ b5a22d43660707a2035afbde9a0d6c8759028fb81c569ed84666bf97b07b56356df2\ 2fa4098042ec174fc3d2c93801ef0ca3801983f4dd209077ff70406a633c97a7b2a9\ f8133c906d2239c64ea74a2180b4de0c32c9b2259cc45f144142919e0e6bc8b13953\ 866a189270fb7c9b2963ab72a9a9735747ed904c0ce0117de98edcf74b989c87d6b2\ f3844be46756bf6b94c0a34a6418c82e2e76d8ca6a97fde52bfbecd37420dcebea27\ b81d81779750ce5881835827a2011837045820cb289275c0c25add86b439534a99ef\ aade738327a2232af71218901e2ae2892ca123590481c2e3fbb37cc85019bc7369ea\ 564d7b4bd33ae1a4c0323d8b6416951d25b370c49daa5c4075ddfb0decdd1289e6d2\ 39106ebb106e6ae98719e9dd43549cf54233cf901beacb315702d8a4efde1fc5350e\ 19172a103390e9c5b6c131b5402f9b43efcbe2864a98ed40b534df3cc72803c37e89\ b9dc9f6ac4e3bc219913f6aa49a10fd587ca737284061daed1dc9ded416799f5d0e9\ 483639d8139dfc05813df276a5fbd3b657d37c2d64774d912982e7854eac3983c284\ 82278fa6f819e3f00cd0f113826f1df92eb7164a1bc9961354cb761a491a27499fbb\ 1a9603d1c07b434c772dcccfa2e6a80b9a452eaff50ff23cada98b065003d74f6f5d\ 0bad46893f9d94d5e308f65b848b4fb726a15099123c9e1b918f0a74e7703bd746c2\ f8e7f5f3d5a4c475469ea2bf37dff5cb3a0b5596b24eb278b5ef849c4143b3429ea6\ d463eb5a17267e81830e60f11e4803663d07ce029ffe9448980ef0daacc315919425\ 1279591d316c7fc10bb853aafbfe6b6f75d3569855113d57aa8ecc911e2023fb49e2\ b8643e00a30bd6c69588eeb19dffacac80d140df33bf09cf16babf76e8d6d82341fe\ cabe76259296b644ee001e10a6f33d4d6cda0bfdb742b1c7d33c702563b3d32dec28\ 07610c0b09c07a9fea3002bd4be5c511f185afbeea7ee11175b70a345ec48658372f\ b8e79cccc14c47b541dcdbce012ee3e4b3f0f3a01576e34edd5d6e2f4f8b49a7f3f7\ Reddy, et al. Expires 14 November 2026 [Page 25] Internet-Draft COSE HPKE PQ May 2026 e831643e6b8b11ce4a4e9b66bdfb9664b5ca5fac6f0089f51cccb4ca076afa0540d0\ 89da1486caa3228245e2d0fcb22cd3b4943a0ea4040b283504dd34b2b85453749613\ e6659f2c91a7652115c4886e7e2030d08edf85db93ae1befe326da6ed92f4c4ac2ea\ 1ce6d5030cfc909a6e821c8d4514d658555e40dd5efa57b6d1c05e85db6284fdbcb7\ 78c4d8e09eea446aa046174e0877998a830974a51b4aee52c896a9f3ee1b5c3bcac9\ bf4663ca5d100b2bf96daaef9e411297c65a66f4819c95298e05fad7991ceba212d8\ 4379475012e925856ad8d8933f09178428321507e99f00c0fd85ad8a73b27a4b48a0\ a9c37752fd6ae03d270d173e43720f26a6e5d004108d8ba5652a5ffb0c0af895af21\ 8481f6a3fb0212c7f530dd39950ff945600e29e917314af5378cd175e269d9b49c53\ 963fdb31e1553eed7008e842375fed0cb377e2fc1d1de540a6fcbf1d324c9f1f04bd\ 42084b6c9f5ac30bde6f7e3a334999b7003a388ac1604fa651e77daba71457e00d0c\ 528b036d1947ab5bb4c0ce2a29ee37f62690b96c655285a70604881a10ba8bad19ec\ 171fa73be914d0571dbf1e6f01fc8a8b83499a6f507905f6027bdffdbdee06259de8\ 5fe11f68a4c414f6c7348f1ec11f1d9777e4c562b964964359842773f29f0091e953\ dadbed437c8d35351bf12ec8f91cdde59bfd10f4bb63153039c8baa683102cb90a29\ 029f691a33c274b4391887a036be6a77e3c9f894f0573ffa5d8c6de1ab01e4af0b42\ 8f4bc371d0d5f7af6d40b108fca27431c7bf2a40dae8049a3aceb56d5773f0801603\ 9d6d0370b5a081a1a0f22998330af2fe1643860546847bee9d67c56747da91b42d60\ c1a4f1686669e34683f24ffceda910176902f75830a520aac9e94fe8d7b006488182\ d6da449ea6d627141553f613070a6498b2ca27a87f50e20c8f30d621fd20fa83187c\ 28 Figure 8: HPKE-8-KE COSE_Encrypt (Hex-Encoded CBOR) A.3. HPKE-9 NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'f3ea0bc050e5462b22ce7bce2af65e7e265d45cd591840175d2c9\ ea658069628', / alg / 3: 56 / HPKE-9 /, / pub / -1: h'6446caaee4cb4d12597fe53280e590c2e04dcc286af32ba11935\ 484cb794ede9860fdb45f68144cb504ff61981456a3ce19ca3afcc65be469d08\ dcaee6239fba8202ee903924273703b04da7664af139cd3d3b1827d05389c8c2\ 86520c3182954a793d5a30a3dc4a8cf7445a462487631314274555f1f63fd3a0\ 6aace0c2c0d3bfe8160669ac47b334805696ab9a4122490399c3207ac6c73476\ c53630654600d403042bb7352b3681998dd5fb255a9c73ab237862d661c24a33\ 726b06ced39b9e06075c4b60aa9a38e262aa5c77cc048c63becaa067ebcdcc6c\ a9d38384ae8b46e5039ebb981066ab99e13952ec9ab18e337492d27d5aaa1fbe\ 5ab58b4246f7b54beda2742072699c597cfb871bab0abbf966a7ffd5347c9bb1\ d7c3c10c1ab78e4422c0b89764e93d2a58229fa046c29c7e24f79d20e3841049\ ca2e943083794e646b877d71824f906419f938b15551ddd83bb8cbc2e32152e5\ fb6f8202167cc3c8e0b57edc31021bea437b5bc4a50144e44c12047521a728c0\ 5ae3041dba5329abb9a0699500861744a65f677088150577807a0165d650a118\ 445f32a67643c1da3248d7a16714650afc649962c5caebc21493f9449e285369\ d9c112133bf3ec21f59b405d0b0a810b5475647b9c5b7ac9602449021e826273\ Reddy, et al. Expires 14 November 2026 [Page 26] Internet-Draft COSE HPKE PQ May 2026 ce4130e3f141acd6142170bddf48757588b5b19c39647a37766637562ab8a4b8\ a28b137d2eb77357a44623047c7e6a6a6ea34073f715b0578f0138879f0050e6\ 47a3d412cc02451f6212695f5955fbdb65a192c0e8976446801e5e712f231c98\ d53518a6e818b9951e111c255b28159ce89db088bf029a35280526f93a1c47a9\ b4cc6b46d98434ee651e236caa6dcb5c83a12f6155412c3bbf44978b172030f9\ 777f597816368233a0e3390972ceb4309c2703282c99275b57603717456471b5\ 99083d4f9c0131b101a632bc6bda0e9dfc556e58a4dde5076244bb4d584a4aa0\ 8ebb2381cc342e56d1c0b7d43a382a0e82ea9498978157819277920f4a7a427a\ 776a06310a67625390dc0592eaaa6e68a512760c1c43ad314caf796662ebfaa6\ da43c6eda55c8c557d538a57644b9120972e82f2541f7ab0f5443bb2682ab1a2\ 4c173ac356c00641622d0c9c5c10e8017414c08a2b7df62818980784c8da0af8\ 6438e8e62c373ab9f82b8288218964a34e6d685d76744e92663a8c51bb2bf93f\ 460bc08ff696d283c81331b3d2306d66a54331314717a778abd7aba4739a3bc8\ 7d7bb9369e7ac6c8782425838f408995acb35cf77384275a8bcd44b025a868f0\ aab0365387a83b898262a849f121a974117c887af2a36a67a482f49609ffe970\ a4a93f4d0518c4951d4641c1f5f824070ca81ac8b49cba4e84c8a7b08737d823\ 321ccaaf06c73d0e54a0999381822a2fca712d8ff82a755677658c0301a49a5d\ 31bbc0b33237005f572726e5374c41e66cf1dc2eea989fa3f518cc1863d4463c\ bb721d4b73956a30ca66a930f7379369c13693056c0a40ce2bfcbec105c4bf21\ 426c0616dc800d6e902e230a62ac625f153587205126d42a8be055cfb7c6bd0e\ eb061d00aeab76c4902b699d188e4c63aa81549949692ea316c69e5ba286b45c\ e4d618f3b3c2bcc491571b611cf4baf807f6c8ffc758c91c7eedc3c0dc821710\ 4981fbed5c62c54a6f19aba106e338a974854b78397e320eacffc8c371edbb92\ 2db1a9755058', / priv / -2: h'b500d252df8c81dd0b3458942bd54496e267aed834e7ba42abd\ ec0e7811d6e23' } Figure 9: HPKE-9 COSE_Key (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 27] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 a50107025820f3ea0bc050e5462b22ce7bce2af65e7e265d45cd591840175d2c9ea6\ 58069628031838205904c06446caaee4cb4d12597fe53280e590c2e04dcc286af32b\ a11935484cb794ede9860fdb45f68144cb504ff61981456a3ce19ca3afcc65be469d\ 08dcaee6239fba8202ee903924273703b04da7664af139cd3d3b1827d05389c8c286\ 520c3182954a793d5a30a3dc4a8cf7445a462487631314274555f1f63fd3a06aace0\ c2c0d3bfe8160669ac47b334805696ab9a4122490399c3207ac6c73476c536306546\ 00d403042bb7352b3681998dd5fb255a9c73ab237862d661c24a33726b06ced39b9e\ 06075c4b60aa9a38e262aa5c77cc048c63becaa067ebcdcc6ca9d38384ae8b46e503\ 9ebb981066ab99e13952ec9ab18e337492d27d5aaa1fbe5ab58b4246f7b54beda274\ 2072699c597cfb871bab0abbf966a7ffd5347c9bb1d7c3c10c1ab78e4422c0b89764\ e93d2a58229fa046c29c7e24f79d20e3841049ca2e943083794e646b877d71824f90\ 6419f938b15551ddd83bb8cbc2e32152e5fb6f8202167cc3c8e0b57edc31021bea43\ 7b5bc4a50144e44c12047521a728c05ae3041dba5329abb9a0699500861744a65f67\ 7088150577807a0165d650a118445f32a67643c1da3248d7a16714650afc649962c5\ caebc21493f9449e285369d9c112133bf3ec21f59b405d0b0a810b5475647b9c5b7a\ c9602449021e826273ce4130e3f141acd6142170bddf48757588b5b19c39647a3776\ 6637562ab8a4b8a28b137d2eb77357a44623047c7e6a6a6ea34073f715b0578f0138\ 879f0050e647a3d412cc02451f6212695f5955fbdb65a192c0e8976446801e5e712f\ 231c98d53518a6e818b9951e111c255b28159ce89db088bf029a35280526f93a1c47\ a9b4cc6b46d98434ee651e236caa6dcb5c83a12f6155412c3bbf44978b172030f977\ 7f597816368233a0e3390972ceb4309c2703282c99275b57603717456471b599083d\ 4f9c0131b101a632bc6bda0e9dfc556e58a4dde5076244bb4d584a4aa08ebb2381cc\ 342e56d1c0b7d43a382a0e82ea9498978157819277920f4a7a427a776a06310a6762\ 5390dc0592eaaa6e68a512760c1c43ad314caf796662ebfaa6da43c6eda55c8c557d\ 538a57644b9120972e82f2541f7ab0f5443bb2682ab1a24c173ac356c00641622d0c\ 9c5c10e8017414c08a2b7df62818980784c8da0af86438e8e62c373ab9f82b828821\ 8964a34e6d685d76744e92663a8c51bb2bf93f460bc08ff696d283c81331b3d2306d\ 66a54331314717a778abd7aba4739a3bc87d7bb9369e7ac6c8782425838f408995ac\ b35cf77384275a8bcd44b025a868f0aab0365387a83b898262a849f121a974117c88\ 7af2a36a67a482f49609ffe970a4a93f4d0518c4951d4641c1f5f824070ca81ac8b4\ 9cba4e84c8a7b08737d823321ccaaf06c73d0e54a0999381822a2fca712d8ff82a75\ 5677658c0301a49a5d31bbc0b33237005f572726e5374c41e66cf1dc2eea989fa3f5\ 18cc1863d4463cbb721d4b73956a30ca66a930f7379369c13693056c0a40ce2bfcbe\ c105c4bf21426c0616dc800d6e902e230a62ac625f153587205126d42a8be055cfb7\ c6bd0eeb061d00aeab76c4902b699d188e4c63aa81549949692ea316c69e5ba286b4\ 5ce4d618f3b3c2bcc491571b611cf4baf807f6c8ffc758c91c7eedc3c0dc82171049\ 81fbed5c62c54a6f19aba106e338a974854b78397e320eacffc8c371edbb922db1a9\ 755058215820b500d252df8c81dd0b3458942bd54496e267aed834e7ba42abdec0e7\ 811d6e23 Figure 10: HPKE-9 COSE_Key (Hex-Encoded CBOR) Reddy, et al. Expires 14 November 2026 [Page 28] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt0 / 16([ / protected / h'a1011838', / unprotected / { / kid / 4: h'f3ea0bc050e5462b22ce7bce2af65e7e265d45cd591840175d2\ c9ea658069628', / ek / -4: h'ff8b5edd7ac5ab9020ddd455aa1738c6140f32481205cd2db43\ 4eb16a52c522a717fa5cb46a3d7dfb918a5901bd8217cf4d5ea2f0004cf90351\ 6d2a8cfbd8ec7b1422bc50a38efe8ccddb6111263a9050a6b984fd9e1aaf7016\ cab7a511dcdb24dcc12dc1d3ff4cafa386f3c2d5ba1984220644b42db05545c7\ c0033f315411b49d2f355d0e8c55aec918cec25336e24a33013bfee1e6bdb7a3\ 4781b82835b51829c4a21d25101dd127552ce1ec504de533d605599a296a8d2e\ 952d347a98ae74bca25184da0ce853e1ebe85495e85999685a465ea666dc4fba\ 055e5c424bb1743798334f1716ee55be47682164a067333d2aca1817785f27e9\ f3640060dca3b12a8e4cd0c2389a5d369922fd69c8e87a521d90f17b4d31d119\ 4b698a5dd28f88ceeec1443c3d5f87d9fb543b305042b2278be1e787a3a2d6a2\ 989cd9ab12d5b692e4ce3dab0ed0a129a14c104a60f4b209609f1778b7c3bea1\ b27cb7e8bb45d3aff3a6ff6cea318037d04278b6afe3dade816758bca8cca43c\ b07cdaff5070fdef0b5004a38926fb96648b83d0db20cedec1d2c7ac7a9aacfb\ fd1ca6d63bb274e6200c023e4f2ca469579d6df4386a7cb393226100c69204fa\ d3ac5c9326c253c02fe950da8e5a85c5bd29acb044714d97571c108de1eeccde\ 7b26789070b29a3f26b7bafe786238cbbb623bc5528a1100b37ede676a0cf5e9\ 1848399ff5aa48fe5721f05fd2e0c3a8a06e238754bee990795d565f12bea6b2\ 148d0ba5e08443ec202b57b5a0cdecbdf9f5ce5fc896136047d73baef5a47762\ 73ac6a1a11b56ac19d68719be1a96e12d17130aa712566a940ad1dfa7468a96e\ b76945ca92ae09878cd82c8a5f07417243a02caab38b512eaf1653f65c1e56a1\ b31daa703885ccc0f129eff8c13b98be82ce8229554f1f6a2524354cd6ebd7be\ ec66f71b43542c3270085ea637f2f717380f6c04d9eb4c63f957a46905767bde\ aa4901adf91ab16e74d54f3cc92b692534ee0a9d53d6fff7d80b9253a8108d3a\ baa5facf066f4eb95df036b6910eb3a0587a19271e74f25b4e8269396f1daee6\ 2aec20992057232cb4d36bd3cba28e7bc8bef5326d49608bfc4f5839b986f140\ 32928b4b86b99d24bfdb3c7d2bb7bf15926e8bf3a2b2adff73828b595b1535d4\ 610c1f459419d1d6214358b2f922371be87bb7c3b8de65f7327a6735f4fb51a0\ fbef85f61c1833511f8c9c0bced4ffdafa7d5c926dbafa4d0b39970e7e80266f\ a288b55dab74200e636f23811cfd0d62504deb2f73fd06c389ca44409c8c700d\ ecb6ed37735dbf34df79725cc526e12b0f791617c4b8a86f862ea07b30b018e0\ ce91e11d143983cdf8d348d7b82d5d8f9eb41fc9aa61a39da5be90ec402b4753\ 182218d92583d474bb1b8f5d14e7018c269198b7678afde34645fbcbbc284a07\ 80f15786189d06723ca4cd719bbdf396e68fc0745e00357cf806c1d329dcc629\ 33619a1df84a6eb04ac73e95745484c37bd43ee4c9d4aaaca0f3b305e10b2781\ f204e2227491206b016cf339f16e5bc596976bbe4654efe2a98bd6d919120600\ 6d71daf91ef67' }, / ciphertext / h'e254aa60ccf2d64fa22a94cd2e03c860bf6d6e5f45f785bf7\ 3e0bfa2a232e6d3184bfa52da8ff15505dc214c61b242021d0a65482a415674d\ b4f4a16318b7bc3c37e3d04e558d0a57d69280644a30fef16ca29b771d0e76a8\ 036c3bab729645c86ff622fe75f5b7a66f476c945732d694e8ac25bebf500d9c\ Reddy, et al. Expires 14 November 2026 [Page 29] Internet-Draft COSE HPKE PQ May 2026 84d88a6594cb28e2d63aa677cb71cd98f972ee2598363eea15e018e2365a889e\ 323b26385007a0016833c0319db0a3ca6c346fa28b8612d30bd02019f67e1427\ 49fb1c728e01c91f20e065c703c1f3cca002eeac8b09d104d02f797a2b43e1f6\ 125773e3378ef6eb18bea6830a4d3ae2e55488183c2331c8a63bcdda3d98b185\ bd6ea6ae590bee18f9d44de3350cf6a7f2f3aeb42ed03408527709e1321f1ff8\ 0ae0943fb213fed63' ]) Figure 11: HPKE-9 COSE_Encrypt0 (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 30] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 d08344a1011838a2045820f3ea0bc050e5462b22ce7bce2af65e7e265d45cd591840\ 175d2c9ea65806962823590460ff8b5edd7ac5ab9020ddd455aa1738c6140f324812\ 05cd2db434eb16a52c522a717fa5cb46a3d7dfb918a5901bd8217cf4d5ea2f0004cf\ 903516d2a8cfbd8ec7b1422bc50a38efe8ccddb6111263a9050a6b984fd9e1aaf701\ 6cab7a511dcdb24dcc12dc1d3ff4cafa386f3c2d5ba1984220644b42db05545c7c00\ 33f315411b49d2f355d0e8c55aec918cec25336e24a33013bfee1e6bdb7a34781b82\ 835b51829c4a21d25101dd127552ce1ec504de533d605599a296a8d2e952d347a98a\ e74bca25184da0ce853e1ebe85495e85999685a465ea666dc4fba055e5c424bb1743\ 798334f1716ee55be47682164a067333d2aca1817785f27e9f3640060dca3b12a8e4\ cd0c2389a5d369922fd69c8e87a521d90f17b4d31d1194b698a5dd28f88ceeec1443\ c3d5f87d9fb543b305042b2278be1e787a3a2d6a2989cd9ab12d5b692e4ce3dab0ed\ 0a129a14c104a60f4b209609f1778b7c3bea1b27cb7e8bb45d3aff3a6ff6cea31803\ 7d04278b6afe3dade816758bca8cca43cb07cdaff5070fdef0b5004a38926fb96648\ b83d0db20cedec1d2c7ac7a9aacfbfd1ca6d63bb274e6200c023e4f2ca469579d6df\ 4386a7cb393226100c69204fad3ac5c9326c253c02fe950da8e5a85c5bd29acb0447\ 14d97571c108de1eeccde7b26789070b29a3f26b7bafe786238cbbb623bc5528a110\ 0b37ede676a0cf5e91848399ff5aa48fe5721f05fd2e0c3a8a06e238754bee990795\ d565f12bea6b2148d0ba5e08443ec202b57b5a0cdecbdf9f5ce5fc896136047d73ba\ ef5a4776273ac6a1a11b56ac19d68719be1a96e12d17130aa712566a940ad1dfa746\ 8a96eb76945ca92ae09878cd82c8a5f07417243a02caab38b512eaf1653f65c1e56a\ 1b31daa703885ccc0f129eff8c13b98be82ce8229554f1f6a2524354cd6ebd7beec6\ 6f71b43542c3270085ea637f2f717380f6c04d9eb4c63f957a46905767bdeaa4901a\ df91ab16e74d54f3cc92b692534ee0a9d53d6fff7d80b9253a8108d3abaa5facf066\ f4eb95df036b6910eb3a0587a19271e74f25b4e8269396f1daee62aec20992057232\ cb4d36bd3cba28e7bc8bef5326d49608bfc4f5839b986f14032928b4b86b99d24bfd\ b3c7d2bb7bf15926e8bf3a2b2adff73828b595b1535d4610c1f459419d1d6214358b\ 2f922371be87bb7c3b8de65f7327a6735f4fb51a0fbef85f61c1833511f8c9c0bced\ 4ffdafa7d5c926dbafa4d0b39970e7e80266fa288b55dab74200e636f23811cfd0d6\ 2504deb2f73fd06c389ca44409c8c700decb6ed37735dbf34df79725cc526e12b0f7\ 91617c4b8a86f862ea07b30b018e0ce91e11d143983cdf8d348d7b82d5d8f9eb41fc\ 9aa61a39da5be90ec402b4753182218d92583d474bb1b8f5d14e7018c269198b7678\ afde34645fbcbbc284a0780f15786189d06723ca4cd719bbdf396e68fc0745e00357\ cf806c1d329dcc62933619a1df84a6eb04ac73e95745484c37bd43ee4c9d4aaaca0f\ 3b305e10b2781f204e2227491206b016cf339f16e5bc596976bbe4654efe2a98bd6d\ 9191206006d71daf91ef67590121e254aa60ccf2d64fa22a94cd2e03c860bf6d6e5f\ 45f785bf73e0bfa2a232e6d3184bfa52da8ff15505dc214c61b242021d0a65482a41\ 5674db4f4a16318b7bc3c37e3d04e558d0a57d69280644a30fef16ca29b771d0e76a\ 8036c3bab729645c86ff622fe75f5b7a66f476c945732d694e8ac25bebf500d9c84d\ 88a6594cb28e2d63aa677cb71cd98f972ee2598363eea15e018e2365a889e323b263\ 85007a0016833c0319db0a3ca6c346fa28b8612d30bd02019f67e142749fb1c728e0\ 1c91f20e065c703c1f3cca002eeac8b09d104d02f797a2b43e1f6125773e3378ef6e\ b18bea6830a4d3ae2e55488183c2331c8a63bcdda3d98b185bd6ea6ae590bee18f9d\ 44de3350cf6a7f2f3aeb42ed03408527709e1321f1ff80ae0943fb213fed63 Figure 12: HPKE-9 COSE_Encrypt0 (Hex-Encoded CBOR) Reddy, et al. Expires 14 November 2026 [Page 31] Internet-Draft COSE HPKE PQ May 2026 A.4. HPKE-9-KE NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'1bac0382c69ab1d21edc61bd062af6bfbef532d1639afb31443c1\ b4b377de735', / alg / 3: 57 / HPKE-9-KE /, / pub / -1: h'f2b1ac0dc6035588075c97681bfcb8b2795fff367627b209fddc\ 8669fa14fbc3c1a9d49be1d28002080bbd42ce8bf930ab109d2d7aa1eec8a73e\ 550f11001779a2139ce91826108937fb6958105b65c942e2c01734722d500578\ 29f026120ca59742a2a8a4688584238704a548042103d37000f26160c8193d69\ 037f5cc525ec53fe9aca7252c647353e024b800ae99c6e812b26a19821175755\ f37b26a7c85df70d23f4024a9729b8093fc0c396c4e223d96c5d08c31f775401\ 14aa008b570cfbf72e2f5256c0e2b94ac0bb14a83960965d64f279dd190552eb\ 193eb85c5ac64cb0e15726680e8de57d6d4580d67a4a109b7b9c3794f4419b20\ 255e97e44286b8877b5b5cc783858140ab081bc4a4997d7746a6e63ab061007e\ 5a6c156772055473367393426ff3078649c9b1a0aaad232611427b5c1a5359b7\ 5494c34c322abd3dc7765b0bccca866635a73fc4a9a4e55c6406aa2b59467789\ e57070662dedc64eda6bc9c2294271cb33e934c8667bb2989539efe279d7411b\ 55f197481377fc10a97f01c002a57ead969be6858f15e6108a48c01e279b9428\ 0dedb48a97a53e342a6868f03e9f54378cc63ebf3172e2268cf1385fa177735d\ 0a34a0b0afc8e6786aa96fe04a98411161e7544de899329397aa51468799a015\ ff2ca3ef00449193480d634ecbb640ba7683979b5716951a3e61cb4384505757\ c203c636ee043fe27398db3747867ab5d963abbcd37e0eb7462344a1a4d5b301\ 132d33aca20d7515db247f6fa2930f2ab46323334021c1421b1cad708dd90c57\ 7788478fe823673a099629ba5f26c696b1ba11a324bc829fc2e859ee8c514ee0\ b78462414a4329b50360dd387896ea25f8597b59ea4cd2f398395c9875100d7a\ ccc9e964ca6490adcd484f712073788997683a8d78202df632015e9a095fa9bc\ 45588ce1b5bc620b51eaf2b671e356e7258201f380f4d9a204302115a30d4e7b\ 9e8acb6bd9e109873159db026c4f5306faf1b6108cae50d06ac2536356f478bd\ f10058e99e06e039bfb072df272c38c16fda1936786b2c233984f3a64e8f93a3\ d7541614f46b48cc79ccb743bb47a9fe93c260d522712b5c0ed22fcbea5f276b\ 84741a09e61744f5db881993a54dea3321675e11c06bbfeb042662a4ee135e39\ 20695690256034c34d5a6f3a293e989011fe16cd9df098e79b050fb0becf139f\ ae341d63058b0d2487e665782102b3b1e27cc75c3971b596cdb52a176a4d6410\ c40234a98aaa95c603808a468ec3331a58011134e797e8d15892681ada744497\ 9b78eb0a13bdba814d2c4130ec5c4b72826f399372aacb55f4bd09c8b90da01d\ 52369df0dccc401a07cb05880054c0f01978a7c71bec6a91f45709615b0ce909\ 5c8dc1826792a16a18183a5047e65c3a6d1322e3c2731eb4566b5a2d5f1997a6\ b70b17842204a1197caa47ad2b2cce508028e2b2b651bbff1b4d3d167f51e666\ 793462c875950c27104b33365bd53fee17c66be044ae65b6d023418ada966661\ 2498645c8b62b13fb70971eb935e3a5801c5569b5c78655375fc9b428ac094e5\ e803a17222f2e147c198a02a1701501212f807a9bd228d7420371ea796cf274a\ 691ccce87775884ca239065dcf8a5c183ae472c6ce82252908718cfce3de2003\ e567c0ea46387a5b16bc3bc630cab7c966ceaf2d47008d6f899f901a36940559\ 4fd575b8530d', Reddy, et al. Expires 14 November 2026 [Page 32] Internet-Draft COSE HPKE PQ May 2026 / priv / -2: h'abf68310c6694408db8aa1f03b6def29c80899889e4aa52c08a\ ef059912cabc6' } Figure 13: HPKE-9-KE COSE_Key (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 a501070258201bac0382c69ab1d21edc61bd062af6bfbef532d1639afb31443c1b4b\ 377de735031839205904c0f2b1ac0dc6035588075c97681bfcb8b2795fff367627b2\ 09fddc8669fa14fbc3c1a9d49be1d28002080bbd42ce8bf930ab109d2d7aa1eec8a7\ 3e550f11001779a2139ce91826108937fb6958105b65c942e2c01734722d50057829\ f026120ca59742a2a8a4688584238704a548042103d37000f26160c8193d69037f5c\ c525ec53fe9aca7252c647353e024b800ae99c6e812b26a19821175755f37b26a7c8\ 5df70d23f4024a9729b8093fc0c396c4e223d96c5d08c31f77540114aa008b570cfb\ f72e2f5256c0e2b94ac0bb14a83960965d64f279dd190552eb193eb85c5ac64cb0e1\ 5726680e8de57d6d4580d67a4a109b7b9c3794f4419b20255e97e44286b8877b5b5c\ c783858140ab081bc4a4997d7746a6e63ab061007e5a6c156772055473367393426f\ f3078649c9b1a0aaad232611427b5c1a5359b75494c34c322abd3dc7765b0bccca86\ 6635a73fc4a9a4e55c6406aa2b59467789e57070662dedc64eda6bc9c2294271cb33\ e934c8667bb2989539efe279d7411b55f197481377fc10a97f01c002a57ead969be6\ 858f15e6108a48c01e279b94280dedb48a97a53e342a6868f03e9f54378cc63ebf31\ 72e2268cf1385fa177735d0a34a0b0afc8e6786aa96fe04a98411161e7544de89932\ 9397aa51468799a015ff2ca3ef00449193480d634ecbb640ba7683979b5716951a3e\ 61cb4384505757c203c636ee043fe27398db3747867ab5d963abbcd37e0eb7462344\ a1a4d5b301132d33aca20d7515db247f6fa2930f2ab46323334021c1421b1cad708d\ d90c577788478fe823673a099629ba5f26c696b1ba11a324bc829fc2e859ee8c514e\ e0b78462414a4329b50360dd387896ea25f8597b59ea4cd2f398395c9875100d7acc\ c9e964ca6490adcd484f712073788997683a8d78202df632015e9a095fa9bc45588c\ e1b5bc620b51eaf2b671e356e7258201f380f4d9a204302115a30d4e7b9e8acb6bd9\ e109873159db026c4f5306faf1b6108cae50d06ac2536356f478bdf10058e99e06e0\ 39bfb072df272c38c16fda1936786b2c233984f3a64e8f93a3d7541614f46b48cc79\ ccb743bb47a9fe93c260d522712b5c0ed22fcbea5f276b84741a09e61744f5db8819\ 93a54dea3321675e11c06bbfeb042662a4ee135e3920695690256034c34d5a6f3a29\ 3e989011fe16cd9df098e79b050fb0becf139fae341d63058b0d2487e665782102b3\ b1e27cc75c3971b596cdb52a176a4d6410c40234a98aaa95c603808a468ec3331a58\ 011134e797e8d15892681ada7444979b78eb0a13bdba814d2c4130ec5c4b72826f39\ 9372aacb55f4bd09c8b90da01d52369df0dccc401a07cb05880054c0f01978a7c71b\ ec6a91f45709615b0ce9095c8dc1826792a16a18183a5047e65c3a6d1322e3c2731e\ b4566b5a2d5f1997a6b70b17842204a1197caa47ad2b2cce508028e2b2b651bbff1b\ 4d3d167f51e666793462c875950c27104b33365bd53fee17c66be044ae65b6d02341\ 8ada9666612498645c8b62b13fb70971eb935e3a5801c5569b5c78655375fc9b428a\ c094e5e803a17222f2e147c198a02a1701501212f807a9bd228d7420371ea796cf27\ 4a691ccce87775884ca239065dcf8a5c183ae472c6ce82252908718cfce3de2003e5\ 67c0ea46387a5b16bc3bc630cab7c966ceaf2d47008d6f899f901a369405594fd575\ b8530d215820abf68310c6694408db8aa1f03b6def29c80899889e4aa52c08aef059\ 912cabc6 Reddy, et al. Expires 14 November 2026 [Page 33] Internet-Draft COSE HPKE PQ May 2026 Figure 14: HPKE-9-KE COSE_Key (Hex-Encoded CBOR) NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt / 96([ / protected / h'a10103', / unprotected / { / iv / 5: h'fd586d64c8d6f44930c12b0a' }, / ciphertext / h'6e6abc1b00632d6607e8f5e673544e72a18a8b0602fd7497d\ d58f27d109b4560ba367fa0a8391b974d08eade4c5e0aaa7da1faa7906c82381\ 4e3ef41d03ac857d16077a76f2169e952d8d6ace596005f5b951d74b9f275e33\ 7175186d5069477188bcc6e5405798009fc7f7552026713f927f12a0612def3f\ c5552cbc87e68bb7dabbc2d44fa4f1a34eecb3b4c0e42894c79e71c16ccca6a2\ 2dfbce49bb682fc207cee21ca765589dceb807d03d497b85a2eb0c411439dae1\ ea47179dfa4fc7ea7550a6a013c453ba2da105810a9ce0e18555da87a70ece33\ acef5776d768277b437e88e80d259ceaaae0c7271e51fac2b08f6d91428b5d0b\ 4703473f2a4345fa0d04c79d77fb222068b4233765c8c4d23c0dd5e850da551b\ 84f77099a77eab71a', / recipients / [ [ / protected / h'a20118390458201bac0382c69ab1d21edc61bd062af6bf\ bef532d1639afb31443c1b4b377de735', / unprotected / { / ek / -4: h'37695f02689bbe11fd8d98bb22c4a987e16a3c275f6d2b8\ 64b48228e375d67ff5030a8854b0f605820c5d4656b1344e562f13dcfe407206\ 31d05e0d361369a4bc099d0a914de0c2e73a04242d5546f172e0142b6103f321\ a8bf62f943c5f4078d3b4ae195145ecb1cf72ef0ad778d6d7dc17661ae7c5f93\ b926f36cb46182566cbff401ae690ec4d1a6fceb049926b53986ee535a939a1d\ 57dc0bb5fdbb7d1b568bea28fa2c9b19b2378dcc9d3677d9920d636b2e4c7745\ 85b2341dc8382d535787ad21cdd64e30007eb6ec0250f384e5ed4e78de1389ba\ b2fc4a075e051332dd60008325581d0605373d33b42526dec1827386cb8c0b31\ 7cec6457e46187789ec33ffbc936da78435dd4b6f0c950cf4ad7ed0a28396b21\ d9fae4a12fc78934820ddd09784b1e2fe0f79f88a762319eb8ccddf1629e4253\ d6ba850baae98b46e03ebccf0664ea2300d67145ad627d01bcda46d267aaf248\ 47fa489418024dcb051735d7f5c674b894fb9117aa631a01acdf2458b8d088af\ d7e8c1f8c4e6abf4e31c3587dd33ad8385413508d9bf2b2aaf9fce48a2004007\ 7cc671053e659f5f1313e44d3abe4cae01ce61e98bb8a2caa7ae611507465a1e\ 45c707ab1379189e2452685dbe7af446f35df8a4e0c5a0f1c63f1014ef90f822\ 8259a054aa12347ae5658441c3e9442d51689fa31d2ffa1fb9009e1c095039f5\ 37cb7d34bc48b8a4a4f9483e14a560a8fe62038bf9df51e0c674ea07542d3f25\ fadb5ebb87b5cc1a2f52ec27312e7cd73df864fe257b46c56398d594fca2bcb2\ b8330d1cc912cd9a2e0c29d260e0ee8c4e5913c131091bbf50eafd6485caac33\ 009a3974f4b314d4c5cec2f7e0b8f00ae81443fc5bb174eafe3b7cbb6a0db010\ d109355263b2fb4fb2f0481d13084a11260000462a87e0eb65a91bab7a6e0823\ 1eb28d5739ba20426c032349afb9588635cfeb3e4ae9a93c6a0d6df47c7841b6\ 9f2c0a2c49b32a7dcf56c93c4de3ee273b84f69c4c43fb43556ab3638238bfe6\ c54d200dedb44175230786aa41922866cbedf49e00f8e6629aabd125bcff64bd\ Reddy, et al. Expires 14 November 2026 [Page 34] Internet-Draft COSE HPKE PQ May 2026 533a7cf2cfdc13c5cce4a15411a31f0855b54cd74864bef084da705b6625fc58\ 931398e757906e973113d6f4229e88dcb9cc8686a900936d53b591b38f967156\ 692539b4d48dbb0ae241c0064a2debb1dc7b90f47c23f2fccff5cab8b5f057e8\ c518e33c766bc4253a30ae9637ff4d6b1f96d4e673a1a12cc85d129ccb4fd01b\ 475dbdfcc876b65dabdb1fbe5f4079298113314549690b49fb6bcae99c106dfd\ 313ccdf6176635b9041eb082f7b10f903b7d01a9c49a14b2279a518922c48fb3\ d90d1f4069cd0c753b07895cabc197e8dddb5a371265501cd8b6f8531cd116a3\ 8d28e292371c9c2ba7c579811f3420265131b55bd1595d5c7a6a95ed3c88e42a\ f43f713704aae8848fbfaf2ade792414f1cf5f0f2181f1bb8a8be8233350f0f8\ 42ea2910b34343c3118d472369d77be9a7399238b31becfcea9a7406bc3703c7\ a30bddbf128e6e769aca976239c5a84a839cb9e4c05b1f255779d4cb5dce9995\ 3f196e90be4f3d813' }, / ciphertext / h'bd5b7833e43a7ce20b533599665d795fdcc8d3e344270\ 425f88d6c778f75b57c5eeb7cf0adc82fe546939cc4b4507998' ] ] ]) Figure 15: HPKE-9-KE COSE_Encrypt (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 d8608443a10103a1054cfd586d64c8d6f44930c12b0a5901216e6abc1b00632d6607\ e8f5e673544e72a18a8b0602fd7497dd58f27d109b4560ba367fa0a8391b974d08ea\ de4c5e0aaa7da1faa7906c823814e3ef41d03ac857d16077a76f2169e952d8d6ace5\ 96005f5b951d74b9f275e337175186d5069477188bcc6e5405798009fc7f75520267\ 13f927f12a0612def3fc5552cbc87e68bb7dabbc2d44fa4f1a34eecb3b4c0e42894c\ 79e71c16ccca6a22dfbce49bb682fc207cee21ca765589dceb807d03d497b85a2eb0\ c411439dae1ea47179dfa4fc7ea7550a6a013c453ba2da105810a9ce0e18555da87a\ 70ece33acef5776d768277b437e88e80d259ceaaae0c7271e51fac2b08f6d91428b5\ d0b4703473f2a4345fa0d04c79d77fb222068b4233765c8c4d23c0dd5e850da551b8\ 4f77099a77eab71a81835827a20118390458201bac0382c69ab1d21edc61bd062af6\ bfbef532d1639afb31443c1b4b377de735a12359046037695f02689bbe11fd8d98bb\ 22c4a987e16a3c275f6d2b864b48228e375d67ff5030a8854b0f605820c5d4656b13\ 44e562f13dcfe40720631d05e0d361369a4bc099d0a914de0c2e73a04242d5546f17\ 2e0142b6103f321a8bf62f943c5f4078d3b4ae195145ecb1cf72ef0ad778d6d7dc17\ 661ae7c5f93b926f36cb46182566cbff401ae690ec4d1a6fceb049926b53986ee535\ a939a1d57dc0bb5fdbb7d1b568bea28fa2c9b19b2378dcc9d3677d9920d636b2e4c7\ 74585b2341dc8382d535787ad21cdd64e30007eb6ec0250f384e5ed4e78de1389bab\ 2fc4a075e051332dd60008325581d0605373d33b42526dec1827386cb8c0b317cec6\ 457e46187789ec33ffbc936da78435dd4b6f0c950cf4ad7ed0a28396b21d9fae4a12\ fc78934820ddd09784b1e2fe0f79f88a762319eb8ccddf1629e4253d6ba850baae98\ b46e03ebccf0664ea2300d67145ad627d01bcda46d267aaf24847fa489418024dcb0\ 51735d7f5c674b894fb9117aa631a01acdf2458b8d088afd7e8c1f8c4e6abf4e31c3\ 587dd33ad8385413508d9bf2b2aaf9fce48a20040077cc671053e659f5f1313e44d3\ abe4cae01ce61e98bb8a2caa7ae611507465a1e45c707ab1379189e2452685dbe7af\ 446f35df8a4e0c5a0f1c63f1014ef90f8228259a054aa12347ae5658441c3e9442d5\ Reddy, et al. Expires 14 November 2026 [Page 35] Internet-Draft COSE HPKE PQ May 2026 1689fa31d2ffa1fb9009e1c095039f537cb7d34bc48b8a4a4f9483e14a560a8fe620\ 38bf9df51e0c674ea07542d3f25fadb5ebb87b5cc1a2f52ec27312e7cd73df864fe2\ 57b46c56398d594fca2bcb2b8330d1cc912cd9a2e0c29d260e0ee8c4e5913c131091\ bbf50eafd6485caac33009a3974f4b314d4c5cec2f7e0b8f00ae81443fc5bb174eaf\ e3b7cbb6a0db010d109355263b2fb4fb2f0481d13084a11260000462a87e0eb65a91\ bab7a6e08231eb28d5739ba20426c032349afb9588635cfeb3e4ae9a93c6a0d6df47\ c7841b69f2c0a2c49b32a7dcf56c93c4de3ee273b84f69c4c43fb43556ab3638238b\ fe6c54d200dedb44175230786aa41922866cbedf49e00f8e6629aabd125bcff64bd5\ 33a7cf2cfdc13c5cce4a15411a31f0855b54cd74864bef084da705b6625fc5893139\ 8e757906e973113d6f4229e88dcb9cc8686a900936d53b591b38f967156692539b4d\ 48dbb0ae241c0064a2debb1dc7b90f47c23f2fccff5cab8b5f057e8c518e33c766bc\ 4253a30ae9637ff4d6b1f96d4e673a1a12cc85d129ccb4fd01b475dbdfcc876b65da\ bdb1fbe5f4079298113314549690b49fb6bcae99c106dfd313ccdf6176635b9041eb\ 082f7b10f903b7d01a9c49a14b2279a518922c48fb3d90d1f4069cd0c753b07895ca\ bc197e8dddb5a371265501cd8b6f8531cd116a38d28e292371c9c2ba7c579811f342\ 0265131b55bd1595d5c7a6a95ed3c88e42af43f713704aae8848fbfaf2ade792414f\ 1cf5f0f2181f1bb8a8be8233350f0f842ea2910b34343c3118d472369d77be9a7399\ 238b31becfcea9a7406bc3703c7a30bddbf128e6e769aca976239c5a84a839cb9e4c\ 05b1f255779d4cb5dce99953f196e90be4f3d8135830bd5b7833e43a7ce20b533599\ 665d795fdcc8d3e344270425f88d6c778f75b57c5eeb7cf0adc82fe546939cc4b450\ 7998 Figure 16: HPKE-9-KE COSE_Encrypt (Hex-Encoded CBOR) A.5. HPKE-10 NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'b453b5dfd9661a61fd09e46152c5d7daa9f5c04e3622e55e1ac60\ 45a66ffc4c1', / alg / 3: 58 / HPKE-10 /, / pub / -1: h'd4a518aacabdd20862c2816e4898cbd6a2a1661450ba319fe9c5\ c9b524522684a1a4cc9018c76cbbe79325313a16765e51036d5b235fb11023cd\ 0a98802bca07d31665d770ce46250aa4525e57121e681008b923f7f4c82598a9\ 1c85cbd649b8ff69c638843cd0f09bc6c70b37e8b228ab7d8a426dd4ab3de5a6\ bf3d2c119ee9b5e0c56e1c8c99bb9c004313cd4e3c3d4b7127234383c8368f69\ 51b9cc7a8807e996f3723a59f254150444adf4478d3c16873b6c60b36495d8c7\ 31960ac408b0a2e7a6cddca6a08a01c5a79b5c8c8b9c7b00c9c28fdcd07259ac\ 4c5eb12974930642f783c1b5b5b1739f7c0ba54f3c3b6e878705d41c18837383\ bc6221772061eabde4a9aa6cda8a32464d162039c05a4e8e8cb591413db270b0\ 56c57e23f754ad67246ab83224d50e36844c382a31e1cbb3884514dd69012bda\ 4e04a5755a3acbd2406a059532d8386c9892c6e908c92e783833a4b80310260b\ 0a7fdb336314668c6cb642a0aa8fb7e1467bfb97c8056aa18799da301f5a042e\ 6eb440977355778473027421e21a7880f53fb7d9b04bbb03d64777fb39b4b028\ aa45e76f3466a0e7d243140231b946b0f97accc95c7a7591b9c5f3a769413c8a\ fb99eb888f43d6ac012ba0505549b6e4200fba4e365c3471442adbea9557e413\ Reddy, et al. Expires 14 November 2026 [Page 36] Internet-Draft COSE HPKE PQ May 2026 4b7486fc081d9fe48386a7bc8b156ba902344d8985540aae467883804c7af0d3\ 388e6c8fbf0b8441e375d298808fdc3b8ce745f7c76eb6477a52c406a4f7205d\ cb02457acdf6e48ba554022545331681b748172e504861ec33abea601c1b465a\ 7b473d1397b6a9367a6d4537136299657b9bfb17198fba064aca7082b1b62137\ 7ec738ba69ec6eee0b9830c68fe1e9373c4863505c15e4782dccd4a0a7d48e40\ 400f95826cf260a9139b4db18aae27443709761aeaea9ee5229863c30ea66929\ b9a8ce9884046ef5239894318d24313d77033f46b4b9c75b1b493492c86aacf0\ 145af4a82d28c057101d832c5ee6975720292b4a3b342ee1bb7da73481cb65c3\ d448babab7e84178122b6c3345a101eb9b92611dee084807f14899f40ac7b25a\ 26c731d2d69801e8510f794dddd03c9be34d7762645f60c15e64322aa87526c9\ 5c6821cd61a728e6b951aafa70474b7de3f9cd6e494ee68032db965c27689a02\ 2c0090f496a6d7cc4403353ff4cca13153bfa47ea8a01ec60aad29804ae7f689\ 2a91a30ab8b8192930bf544f7970b79ab38934027ff3f8cd975c958d555587d9\ 434934063abb585a598703d8c601344addeb28fc33b938d591cad698fdac1bc4\ b27765e4adb4b644977263efd91dd4b8a00171662e24b97cdc62a8495c8ee81b\ dd6c7674d3c485595cd9d234e8d9b89e77c8114643c3391f0dc535f9d255d0f7\ 1409b01b3f2a2b684a95486270315164b796bd42aa945ca634de126c4daa84ba\ 480cd2b6283e5109fd4baa469b6818564159d49cb76a4423b9ae399034962719\ a6e62ac788c60809234bfc6e6852a389e131035206c92a045f9113b911194ed3\ 5da7d8432b2250efac1572856a9678841de51349dc604c810633734b69cab11c\ 55409a05117c0a23a36502c78b175dd2b8ed1b41b908817f967ed21c760c3aaf\ 8244ce2b3cb9b6b109f4c86f29cb58b1845642c5b3e65cb459302051e2cf5985\ a42d7c62e416001762aa176c826adc90fc54193bb9b0099501e59bad29073100\ e01c9b7246411b032f7706d8c0651f85243a285250db1bb2b277a7d8ba1c415c\ f085668958ae06d1196dd159e30283d49a9a877821923b476e1c0b74c1386502\ ace63259be318506c1991b428260629b7fd410f0ea1cf8f363c8eab3a36936cb\ e113b4c0a8b3a29d72719bcab10154a936aca2c9b9a0c5fc243dab461076c43b\ d156818de7243462cbdb63af86254dee36cbd6427c6ee6c861eca69b52b22d17\ 13d319a90c3818b6f02cca051d43290a6ed4a63b184766b70815e29acd659eea\ a71264238c2f486ccf2c35e8c19488bb557c402fa7c833ac659014203a68386b\ 9d2b3c603300cf96287e5a76c1a8bc1fb802dbb96dc9c12956c5b3f6806140f7\ 26abd0ba87f917ed1a9faedbac5cf05a8b5a465c1233fedbbd57a113ce0b3331\ 414e15da0ac6c71ce4970d5a059169ac980c1cb4f157a76d08202ec39dfc1b09\ f24555d9fc27229e1d1949ad86aaa3564ac6b65d4e282617e7fc1bf03ea6081c\ 8f43f06c5c830426abd0609a7c6d2674069dcd52f63b101c0dbccd607cc88ec3\ fa70717a2095a64d83358b8bf541cd7218f6570ce2a8e280e963f49c9f6d8446\ 3e44c9e468f84da8f9ece0bec085687a87c1c99e6d2c04d804a14fc2303a4a54\ 6123c8f812228d', / priv / -2: h'46ef43c31889ec1756061f3616c5da00f3d1e2ce4c66869d28b\ f72db01a68a7a' } Figure 17: HPKE-10 COSE_Key (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 37] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 a50107025820b453b5dfd9661a61fd09e46152c5d7daa9f5c04e3622e55e1ac6045a\ 66ffc4c103183a20590681d4a518aacabdd20862c2816e4898cbd6a2a1661450ba31\ 9fe9c5c9b524522684a1a4cc9018c76cbbe79325313a16765e51036d5b235fb11023\ cd0a98802bca07d31665d770ce46250aa4525e57121e681008b923f7f4c82598a91c\ 85cbd649b8ff69c638843cd0f09bc6c70b37e8b228ab7d8a426dd4ab3de5a6bf3d2c\ 119ee9b5e0c56e1c8c99bb9c004313cd4e3c3d4b7127234383c8368f6951b9cc7a88\ 07e996f3723a59f254150444adf4478d3c16873b6c60b36495d8c731960ac408b0a2\ e7a6cddca6a08a01c5a79b5c8c8b9c7b00c9c28fdcd07259ac4c5eb12974930642f7\ 83c1b5b5b1739f7c0ba54f3c3b6e878705d41c18837383bc6221772061eabde4a9aa\ 6cda8a32464d162039c05a4e8e8cb591413db270b056c57e23f754ad67246ab83224\ d50e36844c382a31e1cbb3884514dd69012bda4e04a5755a3acbd2406a059532d838\ 6c9892c6e908c92e783833a4b80310260b0a7fdb336314668c6cb642a0aa8fb7e146\ 7bfb97c8056aa18799da301f5a042e6eb440977355778473027421e21a7880f53fb7\ d9b04bbb03d64777fb39b4b028aa45e76f3466a0e7d243140231b946b0f97accc95c\ 7a7591b9c5f3a769413c8afb99eb888f43d6ac012ba0505549b6e4200fba4e365c34\ 71442adbea9557e4134b7486fc081d9fe48386a7bc8b156ba902344d8985540aae46\ 7883804c7af0d3388e6c8fbf0b8441e375d298808fdc3b8ce745f7c76eb6477a52c4\ 06a4f7205dcb02457acdf6e48ba554022545331681b748172e504861ec33abea601c\ 1b465a7b473d1397b6a9367a6d4537136299657b9bfb17198fba064aca7082b1b621\ 377ec738ba69ec6eee0b9830c68fe1e9373c4863505c15e4782dccd4a0a7d48e4040\ 0f95826cf260a9139b4db18aae27443709761aeaea9ee5229863c30ea66929b9a8ce\ 9884046ef5239894318d24313d77033f46b4b9c75b1b493492c86aacf0145af4a82d\ 28c057101d832c5ee6975720292b4a3b342ee1bb7da73481cb65c3d448babab7e841\ 78122b6c3345a101eb9b92611dee084807f14899f40ac7b25a26c731d2d69801e851\ 0f794dddd03c9be34d7762645f60c15e64322aa87526c95c6821cd61a728e6b951aa\ fa70474b7de3f9cd6e494ee68032db965c27689a022c0090f496a6d7cc4403353ff4\ cca13153bfa47ea8a01ec60aad29804ae7f6892a91a30ab8b8192930bf544f7970b7\ 9ab38934027ff3f8cd975c958d555587d9434934063abb585a598703d8c601344add\ eb28fc33b938d591cad698fdac1bc4b27765e4adb4b644977263efd91dd4b8a00171\ 662e24b97cdc62a8495c8ee81bdd6c7674d3c485595cd9d234e8d9b89e77c8114643\ c3391f0dc535f9d255d0f71409b01b3f2a2b684a95486270315164b796bd42aa945c\ a634de126c4daa84ba480cd2b6283e5109fd4baa469b6818564159d49cb76a4423b9\ ae399034962719a6e62ac788c60809234bfc6e6852a389e131035206c92a045f9113\ b911194ed35da7d8432b2250efac1572856a9678841de51349dc604c810633734b69\ cab11c55409a05117c0a23a36502c78b175dd2b8ed1b41b908817f967ed21c760c3a\ af8244ce2b3cb9b6b109f4c86f29cb58b1845642c5b3e65cb459302051e2cf5985a4\ 2d7c62e416001762aa176c826adc90fc54193bb9b0099501e59bad29073100e01c9b\ 7246411b032f7706d8c0651f85243a285250db1bb2b277a7d8ba1c415cf085668958\ ae06d1196dd159e30283d49a9a877821923b476e1c0b74c1386502ace63259be3185\ 06c1991b428260629b7fd410f0ea1cf8f363c8eab3a36936cbe113b4c0a8b3a29d72\ 719bcab10154a936aca2c9b9a0c5fc243dab461076c43bd156818de7243462cbdb63\ af86254dee36cbd6427c6ee6c861eca69b52b22d1713d319a90c3818b6f02cca051d\ 43290a6ed4a63b184766b70815e29acd659eeaa71264238c2f486ccf2c35e8c19488\ bb557c402fa7c833ac659014203a68386b9d2b3c603300cf96287e5a76c1a8bc1fb8\ 02dbb96dc9c12956c5b3f6806140f726abd0ba87f917ed1a9faedbac5cf05a8b5a46\ 5c1233fedbbd57a113ce0b3331414e15da0ac6c71ce4970d5a059169ac980c1cb4f1\ Reddy, et al. Expires 14 November 2026 [Page 38] Internet-Draft COSE HPKE PQ May 2026 57a76d08202ec39dfc1b09f24555d9fc27229e1d1949ad86aaa3564ac6b65d4e2826\ 17e7fc1bf03ea6081c8f43f06c5c830426abd0609a7c6d2674069dcd52f63b101c0d\ bccd607cc88ec3fa70717a2095a64d83358b8bf541cd7218f6570ce2a8e280e963f4\ 9c9f6d84463e44c9e468f84da8f9ece0bec085687a87c1c99e6d2c04d804a14fc230\ 3a4a546123c8f812228d21582046ef43c31889ec1756061f3616c5da00f3d1e2ce4c\ 66869d28bf72db01a68a7a Figure 18: HPKE-10 COSE_Key (Hex-Encoded CBOR) NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt0 / 16([ / protected / h'a101183a', / unprotected / { / kid / 4: h'b453b5dfd9661a61fd09e46152c5d7daa9f5c04e3622e55e1ac\ 6045a66ffc4c1', / ek / -4: h'67b7dda74b774aca23a9a6911c02921c0862f0233a6305a15d0\ 6b7e3c69fc3777df95ca24963cb1ff503cd68901de53c6ca17c09cdcc0d7618d\ 2bc91361330dec4aeef70efc366153363d7809e22721977a81158e46921aa83e\ 89770365974f3bbb5a9bf0190da69aeb745dd8f438c949a39414bd94b9464a35\ 5624d3bfe262ccbf1495b160aad391de27e771f3b1232d68a7e1c7a1f2b2cbda\ 9f99342e838acb9319a71c4f2421fa055653c10cb9ece4cc2a78c366e4400195\ ffb9a55402e2416debb5ecb7e5f9a61f72162468c1b53506fcd50f71926a88f7\ ba10b54cc74444501a90b4c0e5242043a1bb18c678752568a052a4387689f1e3\ 95c0b3aff128c5a8278baf8d201ae8b34350805185b48be05671a3c96be44bff\ a039e78b95166dd3cb9042ea193156f742ad8b703dd34ccc1ff35a73205b3fbb\ 6f1e351b87d2802cd6326ae533038fe195db44e4945988fb7bbd29197b1228b2\ ea25fdca68732b9d133a42dba50a37551f424241e7f22251cb1ed74428f890bd\ 1fc282485eb9173f6a44d209ee89d93439415dfce7b01702314e823d34fa62ff\ eaf27d1743fcf3e901223709d7813700c37c3188c3ddc76da385be3d52425062\ 39306f19f52dd54c4f380111abbd34169dc0459381a5343cb7deec916bf3f0b3\ f7e4c9eaa1a8b3434c84622c8eb5b3b29df4e5874a3cbee6ec581271e70a1150\ fe61d2b906533d5aaba9a11d7585519e53f5c5bfe43918963b7e7df0b49331c2\ 7c54b44cbf4bfb6281fa6e7fdb5a85b11026ee06f2ba45eafbaf478839f658ce\ 2c9bbd735c04d5f60d1295faa4f24d65d59618fcf5659a4914bbad50ca96c661\ 0eb8b48106a449d9a970710db33bf1f7abd750778afc6da78fa1ed8c0d3470ec\ 25242320b7b8ab0547e06212dc3cfa80d86b0e700a81739a227fb8a93ad30626\ 3d40dcd5cd49aeb026c46c035d83710342b4f0367489d4c232c6b6a84d8e73fb\ 431551b5a5f8e113d81e3af95ea74a8179b893eb5a6a045065c8e9feb1150dda\ 174c0a1686585a11c9ff40260a42a1657ee9ef3139250a423be719e2683a7e10\ 59c7d1eb26afe08cd130f6d624d09a161e4fd109b45e3c043699af69ce65825d\ 442546189e5cccf1ac0ceef6045eb864de66e9316206cd90acc0d41311b78980\ 90969ba93ce43f0a46183f823eb19ba2c7161350fc918a4f55a5d8e4a4d1f04f\ c21e478916ebdee4f29f681d92ac702542e3b0bae88a898c56a9d5625553081a\ 3dd62689af2e0e2bc7145e15032ff06e98bd23e29f3a438f838032ae317ccb18\ 7bf39afd8d7e40be882be499acf0d44b35baabb6369a2b4f21d6e0a87e572a9a\ 621d869a616d971827f7ef8a258af50e7e48c4d7c70ce16c1e9beb95a049e469\ 1ec2c51f0a5a9182baa299572618910c2079f7d05fa19284afb3a2afb584623d\ Reddy, et al. Expires 14 November 2026 [Page 39] Internet-Draft COSE HPKE PQ May 2026 2e7ebbec9c69777439ad82b41617124ec6d842e8eeaf849e79d976350f449ad4\ 924c7086fece4b9ed4d463e8c435f7b11fb278e1e442127d8721d0bae6959a14\ 81f9f6d6027259458333bd461fc7c32f95fac938e0f413d0a4076a41299d7849\ 04fb8591e8a644f188ebfa57187ddc1786f8eb2946b980a647960a9f9bb9fd97\ 029008c20aac50fa7b7c316d174fa535ddb1438f53ef9f5a57db7b02924b629b\ 2c1da86ac983a49cc45f00fe40c11d853cfdb4d56715e749caabc4dc1f41b5c6\ 03363b0beee804e42e561ac1420031a9a02d6c8e15bffee44ff21c80fcdfc83a\ baf63d0ae444a2f22138252215a4b3b5dfbf72603c166fc0bf7be5ac66c69e8b\ 6e8b18950851c91dec76ab7def61ef8d0d3a486722cd88ed3a8925a31eeb53d6\ ba267884bfcf5c034b73816a515c433981ae11a7a047d1912c7d20a727bb2b8b\ 08c6495555571968b830b87805c7a1bc9c387532f0e681b729a14e20488f80ab\ 048f9ef980852b29ffe36dacc3dae73ae21656df79f1a53ee16391bab665f3f3\ 7bacf0f804c8e9a38f5303b8766500341ac02324497ff2b2671b81b3ca5bf8ae\ af871058903a72f80c2f7138a87dcff64ca5b39b1ed2b6e4b5e135db23505ff6\ a0dcc0f408b5dd3afe7ca46ecba46686c816602d986b5ed16008063de1ad60a9\ cfbde7326fa9b7b191115a47b3494410549c39616e0008deb32861f197dd02a0\ b4108ec98cad2f2244a0a9a367ec75174f48e175469760bb6f23e45b2fa0673b\ 486bc930d2d31047b618b7f66c82f19514dcd07a6d732e14f62570b9384c33bb\ 29a0ee4d6bc3512aa625ecfea33e7d0228cee953d57ad3ecca0d601cdfcf2101\ 345d13a07c084833d042d987185689239d390c3970f535c9a35fac1482ecb344\ bbf0f484cf4f771' }, / ciphertext / h'e2d88c89966fb4430e7977a3fcdaa50f3ab9bdf429f4247b6\ d32d176893f18665f8c14fc4ced6c60ced9d6d45144b0dab87e23f0f5d69d99b\ 74f5f1dcb732b0d18f676e436da558df3518828510844e432342ed0a95b2ed5d\ b4664368f3769ea001191e27bf32b23bdb8fd63c34e7bc41ae41f7324186db80\ 7e6f79103cf28c8ec6120dec5dfc6b721e09589c3aab520932c5f14c789247de\ e62aa26ab9552b2270730db829314d80ae20235050bb28dd54496bcbf5579a53\ ff824f33595e92b4676f63da7a5ee6eb5a209b9842450dc7a12310141c9ded08\ 7b29e8b4f05629f931e8eaf8b88b11f0e4cc7579edfb131086b9c289eb087b1e\ 4bf7cf5615ddafd6d5d9829887a08d2b5784d4c0156b3775989fc32ae8e57934\ 8620f7318985f9b2c' ]) Figure 19: HPKE-10 COSE_Encrypt0 (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 d08344a101183aa2045820b453b5dfd9661a61fd09e46152c5d7daa9f5c04e3622e5\ 5e1ac6045a66ffc4c12359068167b7dda74b774aca23a9a6911c02921c0862f0233a\ 6305a15d06b7e3c69fc3777df95ca24963cb1ff503cd68901de53c6ca17c09cdcc0d\ 7618d2bc91361330dec4aeef70efc366153363d7809e22721977a81158e46921aa83\ e89770365974f3bbb5a9bf0190da69aeb745dd8f438c949a39414bd94b9464a35562\ 4d3bfe262ccbf1495b160aad391de27e771f3b1232d68a7e1c7a1f2b2cbda9f99342\ e838acb9319a71c4f2421fa055653c10cb9ece4cc2a78c366e4400195ffb9a55402e\ 2416debb5ecb7e5f9a61f72162468c1b53506fcd50f71926a88f7ba10b54cc744445\ 01a90b4c0e5242043a1bb18c678752568a052a4387689f1e395c0b3aff128c5a8278\ baf8d201ae8b34350805185b48be05671a3c96be44bffa039e78b95166dd3cb9042e\ Reddy, et al. Expires 14 November 2026 [Page 40] Internet-Draft COSE HPKE PQ May 2026 a193156f742ad8b703dd34ccc1ff35a73205b3fbb6f1e351b87d2802cd6326ae5330\ 38fe195db44e4945988fb7bbd29197b1228b2ea25fdca68732b9d133a42dba50a375\ 51f424241e7f22251cb1ed74428f890bd1fc282485eb9173f6a44d209ee89d934394\ 15dfce7b01702314e823d34fa62ffeaf27d1743fcf3e901223709d7813700c37c318\ 8c3ddc76da385be3d5242506239306f19f52dd54c4f380111abbd34169dc0459381a\ 5343cb7deec916bf3f0b3f7e4c9eaa1a8b3434c84622c8eb5b3b29df4e5874a3cbee\ 6ec581271e70a1150fe61d2b906533d5aaba9a11d7585519e53f5c5bfe43918963b7\ e7df0b49331c27c54b44cbf4bfb6281fa6e7fdb5a85b11026ee06f2ba45eafbaf478\ 839f658ce2c9bbd735c04d5f60d1295faa4f24d65d59618fcf5659a4914bbad50ca9\ 6c6610eb8b48106a449d9a970710db33bf1f7abd750778afc6da78fa1ed8c0d3470e\ c25242320b7b8ab0547e06212dc3cfa80d86b0e700a81739a227fb8a93ad306263d4\ 0dcd5cd49aeb026c46c035d83710342b4f0367489d4c232c6b6a84d8e73fb431551b\ 5a5f8e113d81e3af95ea74a8179b893eb5a6a045065c8e9feb1150dda174c0a16865\ 85a11c9ff40260a42a1657ee9ef3139250a423be719e2683a7e1059c7d1eb26afe08\ cd130f6d624d09a161e4fd109b45e3c043699af69ce65825d442546189e5cccf1ac0\ ceef6045eb864de66e9316206cd90acc0d41311b7898090969ba93ce43f0a46183f8\ 23eb19ba2c7161350fc918a4f55a5d8e4a4d1f04fc21e478916ebdee4f29f681d92a\ c702542e3b0bae88a898c56a9d5625553081a3dd62689af2e0e2bc7145e15032ff06\ e98bd23e29f3a438f838032ae317ccb187bf39afd8d7e40be882be499acf0d44b35b\ aabb6369a2b4f21d6e0a87e572a9a621d869a616d971827f7ef8a258af50e7e48c4d\ 7c70ce16c1e9beb95a049e4691ec2c51f0a5a9182baa299572618910c2079f7d05fa\ 19284afb3a2afb584623d2e7ebbec9c69777439ad82b41617124ec6d842e8eeaf849\ e79d976350f449ad4924c7086fece4b9ed4d463e8c435f7b11fb278e1e442127d872\ 1d0bae6959a1481f9f6d6027259458333bd461fc7c32f95fac938e0f413d0a4076a4\ 1299d784904fb8591e8a644f188ebfa57187ddc1786f8eb2946b980a647960a9f9bb\ 9fd97029008c20aac50fa7b7c316d174fa535ddb1438f53ef9f5a57db7b02924b629\ b2c1da86ac983a49cc45f00fe40c11d853cfdb4d56715e749caabc4dc1f41b5c6033\ 63b0beee804e42e561ac1420031a9a02d6c8e15bffee44ff21c80fcdfc83abaf63d0\ ae444a2f22138252215a4b3b5dfbf72603c166fc0bf7be5ac66c69e8b6e8b1895085\ 1c91dec76ab7def61ef8d0d3a486722cd88ed3a8925a31eeb53d6ba267884bfcf5c0\ 34b73816a515c433981ae11a7a047d1912c7d20a727bb2b8b08c6495555571968b83\ 0b87805c7a1bc9c387532f0e681b729a14e20488f80ab048f9ef980852b29ffe36da\ cc3dae73ae21656df79f1a53ee16391bab665f3f37bacf0f804c8e9a38f5303b8766\ 500341ac02324497ff2b2671b81b3ca5bf8aeaf871058903a72f80c2f7138a87dcff\ 64ca5b39b1ed2b6e4b5e135db23505ff6a0dcc0f408b5dd3afe7ca46ecba46686c81\ 6602d986b5ed16008063de1ad60a9cfbde7326fa9b7b191115a47b3494410549c396\ 16e0008deb32861f197dd02a0b4108ec98cad2f2244a0a9a367ec75174f48e175469\ 760bb6f23e45b2fa0673b486bc930d2d31047b618b7f66c82f19514dcd07a6d732e1\ 4f62570b9384c33bb29a0ee4d6bc3512aa625ecfea33e7d0228cee953d57ad3ecca0\ d601cdfcf2101345d13a07c084833d042d987185689239d390c3970f535c9a35fac1\ 482ecb344bbf0f484cf4f771590121e2d88c89966fb4430e7977a3fcdaa50f3ab9bd\ f429f4247b6d32d176893f18665f8c14fc4ced6c60ced9d6d45144b0dab87e23f0f5\ d69d99b74f5f1dcb732b0d18f676e436da558df3518828510844e432342ed0a95b2e\ d5db4664368f3769ea001191e27bf32b23bdb8fd63c34e7bc41ae41f7324186db807\ e6f79103cf28c8ec6120dec5dfc6b721e09589c3aab520932c5f14c789247dee62aa\ 26ab9552b2270730db829314d80ae20235050bb28dd54496bcbf5579a53ff824f335\ 95e92b4676f63da7a5ee6eb5a209b9842450dc7a12310141c9ded087b29e8b4f0562\ 9f931e8eaf8b88b11f0e4cc7579edfb131086b9c289eb087b1e4bf7cf5615ddafd6d\ Reddy, et al. Expires 14 November 2026 [Page 41] Internet-Draft COSE HPKE PQ May 2026 5d9829887a08d2b5784d4c0156b3775989fc32ae8e579348620f7318985f9b2c Figure 20: HPKE-10 COSE_Encrypt0 (Hex-Encoded CBOR) A.6. HPKE-10-KE NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'79051e8fc75f95a1ea2186f37ea0458a0870a0bc0ea8051422d2e\ b3849505d9a', / alg / 3: 59 / HPKE-10-KE /, / pub / -1: h'f402ceb7d6c085770bea7caec0fcbe72accc80f6c00e12167be8\ 3720503a7c551e89d67f483ba7e736c84811358b960a4fd49328205856509466\ 5028f259ccb5b73bddb372dc336442f8a2e93a6d60d98f4d79b06ae379aac505\ 339a2eaa316dc018504c59154758b962e3b29ea842e1fa7967795c11eb031514\ 3187018994d83188d19690d2a479605510bc54e3250f1d4b77eba679ffc785c4\ 6c694402cac6b7cd6a6b94e737a8900c662c0b152999307c8212c5057a120434\ 242800a5f457a7581a1d693fe6106b0fa58a9706a00c558ef67a5fae116d1c73\ 429b953f15d4cd85e6a6a6985fd0b26974e2cbd811995ada989fbc43b9e83110\ 9081896a01a04978c2931ccf892a2037215b34c0bda08bb57bc1d0539894aa86\ 63f328b033087d84697e4c654dd283c4cc560bf6197534025bd68666abbe82ac\ 394429b0933514c4aacc5bc95559b4571ec19ad564263132654cb18646704fe7\ 86308acbc9a77b51bf3cb7cbe2570da740c5e2b9bbd50920c64bbe0980b3d702\ df1b7bf586a165ba3c173211090229509b21eee0bb55a1bb7f82b38036521086\ 88a8c44a63bb9352f6ac9a265bb6804c53f18faf06745e614d8b74796ee6b489\ e06ed1159db9c41aaab95000f6157d192e14790fb0c99c153a15990b6ae18961\ 13786c4a9755215b3e3c419e29c722043b49108909cf1b76b6c0cf7da81bec39\ 50426a8cb1383977d2bed85605527cba9f7b172f7c1d7dfa0cda41bf5cbc26a4\ f111cb13a2daeabfad861acce1c158fc4274f83e6c1916cb8b8b3aaa7cd6f487\ c7447e2696af00c11fb347732c0158a3b6bc044a54726368e1c72256ca0e57b9\ 5492a36c9215c2b527a848ac3ccc3c42a34c9ed5c30636ea2066728d08f84651\ 2a3d8a0780706aa41e87cc4b70784897271d830c0f4409ede0c4fc787470cb13\ e786ae7aeb89f0f6ae2c7b93e26a241b5b367b164fdee6971b50663ccb69011c\ 8225335ac7641dd4e56aab1ba4ba6995df725af29742db350b53f5c04f366305\ d89067a7b7477bcb420b47e6fa6f9f3047bdb44701b2897504bfb3356285b794\ c6011d192c2d7201cd40c31a99e74edea98762c46a73d94fa3e5b7e3f0948720\ c7aba2bc9f492073114123e46633f884f112327ebba533234f5dd9c9d5d26872\ 29637125328e9648460139042792eec1a9d5927a73cc3b2618920c4593976394\ 6fd1ac6d734ba3a3ccac805692097f039129322a6ac202d03c74c24e6209174b\ ac1dc62732d1024fb53574f4152a04af36eb1a5e5754e6688046bbce9f4a2c06\ 793fbb33c16b20a2f0353b721457327a0c4909613a678d2304ba77d44ceb81c8\ d2801cc00005918c95fa932fa91bb3e00c7e116947b9bac60ef6cc593c0c3696\ 4e873361c0322c95a8203a8a87a9931e828ccee2a92372e78b0cf0416536a68d\ d79285b9107ef712462c7f7dda61bfab1d9d7c8ded49abf64c40ff774b4b89b4\ 005b8f0400a7fd2a2173e80bc114872ee7a8defbadf5551b96d3574f24121c1c\ c2fd381856d0813cb296952bc684dc3979788045823ae7d97639b783fbc25016\ Reddy, et al. Expires 14 November 2026 [Page 42] Internet-Draft COSE HPKE PQ May 2026 3c0dd5f11c7ac0637d758928e849a186c2d9d50ee9f2caa25c6def6514e5959c\ 770623abd5b55843bccfa0b5b3f42a6833ab282b6e2d108ed3795c5cb2242879\ 3001ab294d5c379e107cffa927d617827e369f03595db36771fb8cc179c86cab\ 613b97a1a7a1b867854a74f87417b867934a23b869a9a6d2da2edfe8a75e9373\ b97b11e8260f1b6ab5458025816a0b2403228e04cc44dc6dbc648f835779daac\ 435c1408a4939349c41fddf38d9c705be466474e6890f815bdcf284f33929412\ 8674ee7c7f6de121cebb4c5fc5593897b9b3071d6a5302f0c7a3cce62f2e187b\ 8dd15891e21b6e09313013191241c7b5f8a31600b44fba822d391002d5c0eb02\ 992e08c7c31b160e3b130eeb978250c5c7186ffdd24d5172c3e9741ee2f903c6\ 7108df1141cd59a867a56c466c0a759568dd6ca50528583b587c601693f22011\ 8fcc7a35e9083ec68515bb3f28e84b47fb6d03b1138860ab9ff53f1385058c2a\ b219c64f105bcf73b60d732322eb4ba3c08875a564042031bc239aac67030f45\ 763531763f8a9c8e566136b3151b856183ac783197b466d2cc0606663c25d047\ fdd67b22a4149a97dc166b33b647c8a15dfafa56bc526aa348de7ac5a72f9562\ ba5b08fb453704e6392cb5463fac1c17d64054f082139c0f22ad3dafb11d36f3\ 04b696c54521572694696821b094e8e6b3ce6dccba3a81a1b6c730aa979eff4e\ a78dfba423658a5c8db405d2ffa64470b75421edf04d3c4077989dc1a3e264ac\ bda372b28e2599', / priv / -2: h'b920cf667c309cba49d7c9700061e3ef97be7c6a215bbcce5a1\ 006fbb0c62e2b' } Figure 21: HPKE-10-KE COSE_Key (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 a5010702582079051e8fc75f95a1ea2186f37ea0458a0870a0bc0ea8051422d2eb38\ 49505d9a03183b20590681f402ceb7d6c085770bea7caec0fcbe72accc80f6c00e12\ 167be83720503a7c551e89d67f483ba7e736c84811358b960a4fd493282058565094\ 665028f259ccb5b73bddb372dc336442f8a2e93a6d60d98f4d79b06ae379aac50533\ 9a2eaa316dc018504c59154758b962e3b29ea842e1fa7967795c11eb031514318701\ 8994d83188d19690d2a479605510bc54e3250f1d4b77eba679ffc785c46c694402ca\ c6b7cd6a6b94e737a8900c662c0b152999307c8212c5057a120434242800a5f457a7\ 581a1d693fe6106b0fa58a9706a00c558ef67a5fae116d1c73429b953f15d4cd85e6\ a6a6985fd0b26974e2cbd811995ada989fbc43b9e831109081896a01a04978c2931c\ cf892a2037215b34c0bda08bb57bc1d0539894aa8663f328b033087d84697e4c654d\ d283c4cc560bf6197534025bd68666abbe82ac394429b0933514c4aacc5bc95559b4\ 571ec19ad564263132654cb18646704fe786308acbc9a77b51bf3cb7cbe2570da740\ c5e2b9bbd50920c64bbe0980b3d702df1b7bf586a165ba3c173211090229509b21ee\ e0bb55a1bb7f82b3803652108688a8c44a63bb9352f6ac9a265bb6804c53f18faf06\ 745e614d8b74796ee6b489e06ed1159db9c41aaab95000f6157d192e14790fb0c99c\ 153a15990b6ae1896113786c4a9755215b3e3c419e29c722043b49108909cf1b76b6\ c0cf7da81bec3950426a8cb1383977d2bed85605527cba9f7b172f7c1d7dfa0cda41\ bf5cbc26a4f111cb13a2daeabfad861acce1c158fc4274f83e6c1916cb8b8b3aaa7c\ d6f487c7447e2696af00c11fb347732c0158a3b6bc044a54726368e1c72256ca0e57\ b95492a36c9215c2b527a848ac3ccc3c42a34c9ed5c30636ea2066728d08f846512a\ 3d8a0780706aa41e87cc4b70784897271d830c0f4409ede0c4fc787470cb13e786ae\ 7aeb89f0f6ae2c7b93e26a241b5b367b164fdee6971b50663ccb69011c8225335ac7\ Reddy, et al. Expires 14 November 2026 [Page 43] Internet-Draft COSE HPKE PQ May 2026 641dd4e56aab1ba4ba6995df725af29742db350b53f5c04f366305d89067a7b7477b\ cb420b47e6fa6f9f3047bdb44701b2897504bfb3356285b794c6011d192c2d7201cd\ 40c31a99e74edea98762c46a73d94fa3e5b7e3f0948720c7aba2bc9f492073114123\ e46633f884f112327ebba533234f5dd9c9d5d2687229637125328e96484601390427\ 92eec1a9d5927a73cc3b2618920c45939763946fd1ac6d734ba3a3ccac805692097f\ 039129322a6ac202d03c74c24e6209174bac1dc62732d1024fb53574f4152a04af36\ eb1a5e5754e6688046bbce9f4a2c06793fbb33c16b20a2f0353b721457327a0c4909\ 613a678d2304ba77d44ceb81c8d2801cc00005918c95fa932fa91bb3e00c7e116947\ b9bac60ef6cc593c0c36964e873361c0322c95a8203a8a87a9931e828ccee2a92372\ e78b0cf0416536a68dd79285b9107ef712462c7f7dda61bfab1d9d7c8ded49abf64c\ 40ff774b4b89b4005b8f0400a7fd2a2173e80bc114872ee7a8defbadf5551b96d357\ 4f24121c1cc2fd381856d0813cb296952bc684dc3979788045823ae7d97639b783fb\ c250163c0dd5f11c7ac0637d758928e849a186c2d9d50ee9f2caa25c6def6514e595\ 9c770623abd5b55843bccfa0b5b3f42a6833ab282b6e2d108ed3795c5cb224287930\ 01ab294d5c379e107cffa927d617827e369f03595db36771fb8cc179c86cab613b97\ a1a7a1b867854a74f87417b867934a23b869a9a6d2da2edfe8a75e9373b97b11e826\ 0f1b6ab5458025816a0b2403228e04cc44dc6dbc648f835779daac435c1408a49393\ 49c41fddf38d9c705be466474e6890f815bdcf284f339294128674ee7c7f6de121ce\ bb4c5fc5593897b9b3071d6a5302f0c7a3cce62f2e187b8dd15891e21b6e09313013\ 191241c7b5f8a31600b44fba822d391002d5c0eb02992e08c7c31b160e3b130eeb97\ 8250c5c7186ffdd24d5172c3e9741ee2f903c67108df1141cd59a867a56c466c0a75\ 9568dd6ca50528583b587c601693f220118fcc7a35e9083ec68515bb3f28e84b47fb\ 6d03b1138860ab9ff53f1385058c2ab219c64f105bcf73b60d732322eb4ba3c08875\ a564042031bc239aac67030f45763531763f8a9c8e566136b3151b856183ac783197\ b466d2cc0606663c25d047fdd67b22a4149a97dc166b33b647c8a15dfafa56bc526a\ a348de7ac5a72f9562ba5b08fb453704e6392cb5463fac1c17d64054f082139c0f22\ ad3dafb11d36f304b696c54521572694696821b094e8e6b3ce6dccba3a81a1b6c730\ aa979eff4ea78dfba423658a5c8db405d2ffa64470b75421edf04d3c4077989dc1a3\ e264acbda372b28e2599215820b920cf667c309cba49d7c9700061e3ef97be7c6a21\ 5bbcce5a1006fbb0c62e2b Figure 22: HPKE-10-KE COSE_Key (Hex-Encoded CBOR) NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt / 96([ / protected / h'a10103', / unprotected / { / iv / 5: h'0c747a20a846a6813de21f17' }, / ciphertext / h'cf17007911e2b25fb5cc1fcfb62fb8424a6d4ea8a3cff3474\ dc84a43f847527cf659eb9ac9c563aa98d4447e26d303940e76cf900f19857ee\ c2da96c64a2fd0edd38036f51d076b09aff810c9abfbb4a2e818a064da3154da\ aa6bdb2240bd9dc1ab1faee542ea875f9e5c58f04f9b7132c70b20b9b9b5c582\ 78ca59620ed693de6b2dc675766216b317e5ac82b192350ef1426cd0e8bb18b2\ 9fc3b4314e49ad3ad0e9ee977593712823284068d82af2b4347fa5eb87d3cadd\ 92f40f9ef03d1c59678487b2716a756aecb45f1b39ebf8ae4204a1f784a3a351\ 87c334db817752083706d1c44c6a01f46ed74a34c8523d0c75287c91b57df3cd\ Reddy, et al. Expires 14 November 2026 [Page 44] Internet-Draft COSE HPKE PQ May 2026 76b26c98145feccd6ccaf640857cc8fee4726d834ccac3ecd45b3c154e537571\ 3e327aaf675e5d579', / recipients / [ [ / protected / h'a201183b04582079051e8fc75f95a1ea2186f37ea0458a\ 0870a0bc0ea8051422d2eb3849505d9a', / unprotected / { / ek / -4: h'f2a9112fc88e0ca3a5ae9575603332317b01fb2509b0544\ 0b1cbdd6fed8c246a8d27f979954acdf0f3ecf6e499cef02e535e0a628f0d169\ b3d5f14ac52ae309f00f89294096d2602bfe42a4741be240906ce525057c45d4\ e8b2d6069b0c37920ae1785b93526226e43bb7390d3860a5c1d08b25567054e1\ d53d8568117cddcd12e13bd923dd7976f619d17d6c6a1e29fce3143b83bb2a03\ 2e9242b3d6ec270fd1131cd3ace3741a0d4ae62f43823b02faf8af2ca59426a4\ 88084d5d741aa219ddf16d6430888e438759580127b6cef085cdf7598ed0243e\ 84de61457903ed8d75f9a74f9a425bcbc2d147650631b3930b1a63c0c43c75c2\ a8f95977d8620c30e01ae3c28b79ad691425cad1716c3e17300d79e9e5d4a7c6\ c5f3243233edc9cb1ea43a53a18c29dc5176f7856e45d7cb2c1ca2cab4b94b0f\ ce81bfbbbd45177bbfdc028d39a684388291bf23e4acfdc6d61fa1f4a6ece1ad\ 5afc23675e4bdd8ad1f164b58f84cec337bfeafb1228c3dbbb82fdc54e38a4a4\ 027ea036f4a58eda43388678c19b64bfb7c46f4e6224000a8f695122dd120a5a\ cd8773c2516bf996f6947992513c022e0329ff2973af756422c25846ebb3adda\ 90a7bbbff8267dc91d9d378af8c9aeb07571c4b465c6eafdf830d3aa7f26e593\ ca2423f373b1daf9e11352ba8b7f895630c07a378b5a646a5922f5f5ebb096a8\ 27ca9714200bc5a2a2101526985fa920d4e6be44a3a6126d328d00220a529363\ e62541a3195dfc9ee2607978e99c61dd5d10ab44da385063998d75199c989ebf\ b986c83249ce086119fceb14b85c79ba937b0f6ac234b7789c63a6509527b680\ dde6d785f019aad4f7618b0e7d6ac3202358aa386e1d1c7a669089ea47e82b9a\ 99463202a9d2ddbe60d81d90256a0429cf06a1b79d56a2f8c4acd298ed8d897c\ 07838b66a95ccb06384d587cc79b7404052cb0690a0258ec6889694e383794fe\ 869aa937ebe2b1a998f224c08be34300a563195d072be8f9d9015e3908debc9f\ 5dec0fd4fa5d9d1e365601940ac55973e2ad106ab23064d0c0a24f8976c302cf\ 55dd6a7444dc9eee744c36833e6b9adbff1f2d97b69970e4ce3f234dbbad8679\ 50c17a70ef054c47ae3e75d1690a3b5b39ef7cc6420f4f2c86c78c05e1627088\ 3a0d82411b5b6c385a05a757848e351b4b9f0cf58a014f6ec567d7c97bdbda49\ 609ffbbf9e61ea65e2d3c1f82c584153c43c8c9c7f6ae3850ebf6044a521ee1e\ 93c634cefa0f426158ddb6a5117cb9a2b1f2d6dd5bd6790d3a0e36b8bde827f5\ 723664b51fe0b75c3c0019066b1e32c86472fdad663ad7359548ab58e99650f1\ 37b32770892245f216809a7b7882c7c370f7bd56542bd43b30d920989cea5b6d\ ce62bb44d18b2913267bf1cab194de802e76466bc241fa685db01330d2911bce\ 1218a3e5da7fc7df392a22c579c0d59c1e12cbf4f9da7c5a25b595b17c9f89a3\ 9563b710de8710888ecad66f694766e21ae7b99353c3976fa69cb579e8845b88\ 92a8971f1d87887820beebcc07555643fec0405ab8e5e9c6bebf78b3a00fad9b\ 97c43cfca49103d5d9b2695405a5a239198a78669fc26ef5123c64015c7e73f2\ 3eae5ed252ff6ad4f477f6f61f2e8316ca9282f08a02135ca7ea3f1fc0f45a90\ d804c42ecfd54b69b5b298db29d6a73113fb1eec918b27869dba90524029a0aa\ d1cccb670c975217b3d201e68a958b2797fc0994460ba139b7fe3bedd64bd480\ 163d09e6bc4cdba189fce14965697807f376e12d292c4d6bdc68ad79ad20f887\ d852879dc2fd3c04e076c6507bb2979ef241ac59466a0f95ade0d7196968b911\ Reddy, et al. Expires 14 November 2026 [Page 45] Internet-Draft COSE HPKE PQ May 2026 b4eb4af35c5385a962469c584f149664fbd3024be5a372c5caa0b797806d9ea0\ a2d0cc7fe7cef02c28eb3496f4fda62797424412bfa618b9ae0381548676c46a\ 46a396d30271f16d6ff1363f3ef6c65d8382cd165473b290da2b07c4b9161069\ 38bcf7868b67795adba13739e1638cf9bb6bc70fdc85998c96ac8bd641744593\ a224ebf4a810d28875e57fce6e78830f6e382b00cf214993b18359e4538c5290\ dbeac69e696e280412372c2f5a4c42f5b0ca2b717edcab6b8308b92b07bf81a1\ 52035dbead0b6a1918106a2136284acad6ef314ce861fbc779928a6bf563bd50\ 5962738924778b9b07722e7bef8be2c4562348fabee0b44a2e5c292faf1d125e\ 42942f155d0e2ccb604304c74c681234a55ad8f30ea281012b5912054007f492\ 253384fe74892d5ff2d6f9f417d950ea9c738c1ef3ed322b7cb8cf89710e53fb\ e5a7a3fe13cbb5b61735da4132ee3d411b9cc55bdae719a7df5face00f85ffe0\ 3ca1b2f4bcee85e9baa' }, / ciphertext / h'22d73ba82dc4d024fe6b933349ac0538531495e3cbf9b\ 45e1712d3c170a97f9d33fb2e5eb3a4ee625e8caf2be9a64ca2' ] ] ]) Figure 23: HPKE-10-KE COSE_Encrypt (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 d8608443a10103a1054c0c747a20a846a6813de21f17590121cf17007911e2b25fb5\ cc1fcfb62fb8424a6d4ea8a3cff3474dc84a43f847527cf659eb9ac9c563aa98d444\ 7e26d303940e76cf900f19857eec2da96c64a2fd0edd38036f51d076b09aff810c9a\ bfbb4a2e818a064da3154daaa6bdb2240bd9dc1ab1faee542ea875f9e5c58f04f9b7\ 132c70b20b9b9b5c58278ca59620ed693de6b2dc675766216b317e5ac82b192350ef\ 1426cd0e8bb18b29fc3b4314e49ad3ad0e9ee977593712823284068d82af2b4347fa\ 5eb87d3cadd92f40f9ef03d1c59678487b2716a756aecb45f1b39ebf8ae4204a1f78\ 4a3a35187c334db817752083706d1c44c6a01f46ed74a34c8523d0c75287c91b57df\ 3cd76b26c98145feccd6ccaf640857cc8fee4726d834ccac3ecd45b3c154e5375713\ e327aaf675e5d57981835827a201183b04582079051e8fc75f95a1ea2186f37ea045\ 8a0870a0bc0ea8051422d2eb3849505d9aa123590681f2a9112fc88e0ca3a5ae9575\ 603332317b01fb2509b05440b1cbdd6fed8c246a8d27f979954acdf0f3ecf6e499ce\ f02e535e0a628f0d169b3d5f14ac52ae309f00f89294096d2602bfe42a4741be2409\ 06ce525057c45d4e8b2d6069b0c37920ae1785b93526226e43bb7390d3860a5c1d08\ b25567054e1d53d8568117cddcd12e13bd923dd7976f619d17d6c6a1e29fce3143b8\ 3bb2a032e9242b3d6ec270fd1131cd3ace3741a0d4ae62f43823b02faf8af2ca5942\ 6a488084d5d741aa219ddf16d6430888e438759580127b6cef085cdf7598ed0243e8\ 4de61457903ed8d75f9a74f9a425bcbc2d147650631b3930b1a63c0c43c75c2a8f95\ 977d8620c30e01ae3c28b79ad691425cad1716c3e17300d79e9e5d4a7c6c5f324323\ 3edc9cb1ea43a53a18c29dc5176f7856e45d7cb2c1ca2cab4b94b0fce81bfbbbd451\ 77bbfdc028d39a684388291bf23e4acfdc6d61fa1f4a6ece1ad5afc23675e4bdd8ad\ 1f164b58f84cec337bfeafb1228c3dbbb82fdc54e38a4a4027ea036f4a58eda43388\ 678c19b64bfb7c46f4e6224000a8f695122dd120a5acd8773c2516bf996f69479925\ 13c022e0329ff2973af756422c25846ebb3adda90a7bbbff8267dc91d9d378af8c9a\ eb07571c4b465c6eafdf830d3aa7f26e593ca2423f373b1daf9e11352ba8b7f89563\ Reddy, et al. Expires 14 November 2026 [Page 46] Internet-Draft COSE HPKE PQ May 2026 0c07a378b5a646a5922f5f5ebb096a827ca9714200bc5a2a2101526985fa920d4e6b\ e44a3a6126d328d00220a529363e62541a3195dfc9ee2607978e99c61dd5d10ab44d\ a385063998d75199c989ebfb986c83249ce086119fceb14b85c79ba937b0f6ac234b\ 7789c63a6509527b680dde6d785f019aad4f7618b0e7d6ac3202358aa386e1d1c7a6\ 69089ea47e82b9a99463202a9d2ddbe60d81d90256a0429cf06a1b79d56a2f8c4acd\ 298ed8d897c07838b66a95ccb06384d587cc79b7404052cb0690a0258ec6889694e3\ 83794fe869aa937ebe2b1a998f224c08be34300a563195d072be8f9d9015e3908deb\ c9f5dec0fd4fa5d9d1e365601940ac55973e2ad106ab23064d0c0a24f8976c302cf5\ 5dd6a7444dc9eee744c36833e6b9adbff1f2d97b69970e4ce3f234dbbad867950c17\ a70ef054c47ae3e75d1690a3b5b39ef7cc6420f4f2c86c78c05e16270883a0d82411\ b5b6c385a05a757848e351b4b9f0cf58a014f6ec567d7c97bdbda49609ffbbf9e61e\ a65e2d3c1f82c584153c43c8c9c7f6ae3850ebf6044a521ee1e93c634cefa0f42615\ 8ddb6a5117cb9a2b1f2d6dd5bd6790d3a0e36b8bde827f5723664b51fe0b75c3c001\ 9066b1e32c86472fdad663ad7359548ab58e99650f137b32770892245f216809a7b7\ 882c7c370f7bd56542bd43b30d920989cea5b6dce62bb44d18b2913267bf1cab194d\ e802e76466bc241fa685db01330d2911bce1218a3e5da7fc7df392a22c579c0d59c1\ e12cbf4f9da7c5a25b595b17c9f89a39563b710de8710888ecad66f694766e21ae7b\ 99353c3976fa69cb579e8845b8892a8971f1d87887820beebcc07555643fec0405ab\ 8e5e9c6bebf78b3a00fad9b97c43cfca49103d5d9b2695405a5a239198a78669fc26\ ef5123c64015c7e73f23eae5ed252ff6ad4f477f6f61f2e8316ca9282f08a02135ca\ 7ea3f1fc0f45a90d804c42ecfd54b69b5b298db29d6a73113fb1eec918b27869dba9\ 0524029a0aad1cccb670c975217b3d201e68a958b2797fc0994460ba139b7fe3bedd\ 64bd480163d09e6bc4cdba189fce14965697807f376e12d292c4d6bdc68ad79ad20f\ 887d852879dc2fd3c04e076c6507bb2979ef241ac59466a0f95ade0d7196968b911b\ 4eb4af35c5385a962469c584f149664fbd3024be5a372c5caa0b797806d9ea0a2d0c\ c7fe7cef02c28eb3496f4fda62797424412bfa618b9ae0381548676c46a46a396d30\ 271f16d6ff1363f3ef6c65d8382cd165473b290da2b07c4b916106938bcf7868b677\ 95adba13739e1638cf9bb6bc70fdc85998c96ac8bd641744593a224ebf4a810d2887\ 5e57fce6e78830f6e382b00cf214993b18359e4538c5290dbeac69e696e280412372\ c2f5a4c42f5b0ca2b717edcab6b8308b92b07bf81a152035dbead0b6a1918106a213\ 6284acad6ef314ce861fbc779928a6bf563bd505962738924778b9b07722e7bef8be\ 2c4562348fabee0b44a2e5c292faf1d125e42942f155d0e2ccb604304c74c681234a\ 55ad8f30ea281012b5912054007f492253384fe74892d5ff2d6f9f417d950ea9c738\ c1ef3ed322b7cb8cf89710e53fbe5a7a3fe13cbb5b61735da4132ee3d411b9cc55bd\ ae719a7df5face00f85ffe03ca1b2f4bcee85e9baa583022d73ba82dc4d024fe6b93\ 3349ac0538531495e3cbf9b45e1712d3c170a97f9d33fb2e5eb3a4ee625e8caf2be9\ a64ca2 Figure 24: HPKE-10-KE COSE_Encrypt (Hex-Encoded CBOR) A.7. HPKE-11 Reddy, et al. Expires 14 November 2026 [Page 47] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'400faa06149080d620fa067cabef42e03b05a7705da72188cd273\ 2e034e493dc', / alg / 3: 60 / HPKE-11 /, / pub / -1: h'fc609d52449d94b11ce376a4c3a961938c271278b3b455cfc150\ 25fce33af0c51db9b7cb9cba8a87dc141609bf7e9861dad8c7c01827378b39d2\ 69a22b6616bce298309a13a357a7cff45ab281437c8bbcc8848ab1441c17171f\ 883146a3956ee5d48309e752b186094a42b7989b86fbfcb04ea733c63325b299\ 290b379c9ec3780106510d8aa638102a705348509249b1babdc867a221c168d1\ d9ae132b1cc4c796df11ab689ac996c5830feb1c2d43c296018711601a92715a\ 13f998e5e78e75e55b68f71f07406b1b0c0c8607a4f5ea4bd3d58d156c783b74\ ac9201760ce589bee23d08e7c067403d7ac55d5c360227106af4b49739cb4080\ f31ffd695015f5c59b70bc297c80ac080953e3aa57f13353486d34580bcebc56\ b3582664b21efd2375dd69aaade42948577ae780c393b4c07ae84872ec0d3e9b\ 6b59507ec6f558a4e9108e4c1206873c255b234ae2460dc79103b7a27de46807\ b517d05762f7e7bad01bc07554cfa9b0cd42904c1ebba8b0930e8147c470b598\ 55eb0d27e48e6939a165b3bc84c9adbddb9d1c846e2e5469ebd85dfc70adc829\ 8e931a132dd532ce237cedba33d8a86f6da769103c9199f8c968a60004c1732a\ d953aff9120105636a18bac04cbb4346617d7b77f87592818a7db0aa980fc07f\ 34a9951c8c500ed88b503954f8fc1b049900c3173db00b5f10e05e28b3258fb8\ 95fa98ba47157a14ab40074545f4a10c7742c3ee5a4fed53945c24cc6c84b3ae\ 172a23839d3975a4dcc8cd9d1a2f7dd54235e779e3bc093a33073947bc680a0e\ 96cc326c21aae8973b26fb25a2d8bd6bba7df014c44f5cad01782617b1aedb43\ 354ba99a433c9b106a0ff5d99d650b4ec21c84d1e0a32e39b67ae4a52269936e\ 129f416962442447bfd77264c20a7f891f0773a4609c0662d37fdcd22d899b5c\ aa9b962141c7299813cae683a983a11522b37a39a35f05c6cd3b9b40f420c6d6\ 015792c9fdd1c0e107479e94bdf98c61346291e7d93abf9a033f20c7246377fd\ 3235d863c791dc76cf3276197a949432a3ee02130bca8b3a4c58ec2146b756b4\ b903037ae8b0031fde14458c8de3cba81a178f4589e0d5dd2f74834b85ff01bc\ e4a78e90a712', / priv / -2: h'ca322edfb263988f8c6e07c81206da527199e2e15701563fb65\ 40e4bade3867b7ee9716b72649d2029df4c750bcf64a91bbf3cfc79892b2ba99\ cffa2acddda5b' } Figure 25: HPKE-11 COSE_Key (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 48] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 a50107025820400faa06149080d620fa067cabef42e03b05a7705da72188cd2732e0\ 34e493dc03183c20590320fc609d52449d94b11ce376a4c3a961938c271278b3b455\ cfc15025fce33af0c51db9b7cb9cba8a87dc141609bf7e9861dad8c7c01827378b39\ d269a22b6616bce298309a13a357a7cff45ab281437c8bbcc8848ab1441c17171f88\ 3146a3956ee5d48309e752b186094a42b7989b86fbfcb04ea733c63325b299290b37\ 9c9ec3780106510d8aa638102a705348509249b1babdc867a221c168d1d9ae132b1c\ c4c796df11ab689ac996c5830feb1c2d43c296018711601a92715a13f998e5e78e75\ e55b68f71f07406b1b0c0c8607a4f5ea4bd3d58d156c783b74ac9201760ce589bee2\ 3d08e7c067403d7ac55d5c360227106af4b49739cb4080f31ffd695015f5c59b70bc\ 297c80ac080953e3aa57f13353486d34580bcebc56b3582664b21efd2375dd69aaad\ e42948577ae780c393b4c07ae84872ec0d3e9b6b59507ec6f558a4e9108e4c120687\ 3c255b234ae2460dc79103b7a27de46807b517d05762f7e7bad01bc07554cfa9b0cd\ 42904c1ebba8b0930e8147c470b59855eb0d27e48e6939a165b3bc84c9adbddb9d1c\ 846e2e5469ebd85dfc70adc8298e931a132dd532ce237cedba33d8a86f6da769103c\ 9199f8c968a60004c1732ad953aff9120105636a18bac04cbb4346617d7b77f87592\ 818a7db0aa980fc07f34a9951c8c500ed88b503954f8fc1b049900c3173db00b5f10\ e05e28b3258fb895fa98ba47157a14ab40074545f4a10c7742c3ee5a4fed53945c24\ cc6c84b3ae172a23839d3975a4dcc8cd9d1a2f7dd54235e779e3bc093a33073947bc\ 680a0e96cc326c21aae8973b26fb25a2d8bd6bba7df014c44f5cad01782617b1aedb\ 43354ba99a433c9b106a0ff5d99d650b4ec21c84d1e0a32e39b67ae4a52269936e12\ 9f416962442447bfd77264c20a7f891f0773a4609c0662d37fdcd22d899b5caa9b96\ 2141c7299813cae683a983a11522b37a39a35f05c6cd3b9b40f420c6d6015792c9fd\ d1c0e107479e94bdf98c61346291e7d93abf9a033f20c7246377fd3235d863c791dc\ 76cf3276197a949432a3ee02130bca8b3a4c58ec2146b756b4b903037ae8b0031fde\ 14458c8de3cba81a178f4589e0d5dd2f74834b85ff01bce4a78e90a712215840ca32\ 2edfb263988f8c6e07c81206da527199e2e15701563fb6540e4bade3867b7ee9716b\ 72649d2029df4c750bcf64a91bbf3cfc79892b2ba99cffa2acddda5b Figure 26: HPKE-11 COSE_Key (Hex-Encoded CBOR) Reddy, et al. Expires 14 November 2026 [Page 49] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt0 / 16([ / protected / h'a101183c', / unprotected / { / kid / 4: h'400faa06149080d620fa067cabef42e03b05a7705da72188cd2\ 732e034e493dc', / ek / -4: h'8e6c3c2040aadc5e88394e9f8e64459062d0ae76c941e7e4a20\ 158310056e59cacd8a62ba1569fe2e9b4495c61201afac15702398412e4e92c9\ dfb098ef00ea417a67235b9b4582c83efb1fe47a8d77143d322618aab4960ca6\ ff3bc6e0b0a3a891620f21eb9f877253ae8768d5beb72683ee9d54c375e06a6e\ 460fe963f47aa7950fb246b3432cc75e2b86421363a324fd2baddbbdefa71de7\ f304a6c1aad4e4e0bac4e62daffa1fa05605065d4bdcfab842b2777a35f69eac\ c452037b0efb4c6d7f1522b31e19a5f8d06c10ba42803ab58b4c6106d5c98f88\ 872256fce8d1e7858b9020ffa8243a617077fc51f90dc939ff42ce3cccd62a64\ ad3e45e4d2cadf1353922c73fa503369ea34b9cbbb5b20b2c69b88a5f7fa07c4\ 1c820a1fc0cfc8b702f67407bb1e5c8beecce96b5c925c564cbaebbf874cc60b\ 65ae469e9a28c859220ed3732933891963566a4d4ff744f0716be4fb7b40015d\ 00e138b552500f804a68393086d259318e9dbc2cc17ec3d4d32b3890e31cca17\ eb6cca9f36d6cfb7274fc8cd4d8dcdd0b20fa4e609a5e17a7c60293c308bb00c\ 5abc63fee3f811bac44a39b6175854bf7b923120edd2ab52d3052a373f1762e7\ cc0fee18f550a30667a2054fddb4d498a96407b282671d4e650189fe7544a232\ eb9bcab0d28dda0e523fad70d5bbad428de286e1c7e4f774a125ba577daa0ae1\ 29cd17a40746e484f88c1debdd2101d4cd6becf08cd0a2574aec253045dd4e0e\ 2e21b7c3da70b07712725299a48db218189f7daae5250c22cde5237e64efe366\ ddedd519098de1ccad4a55a1d0a5fd6760b16839d3bb887b3eedd3459c162779\ 129cf62941dc04fae9ae494ded2cad4f082be84bbd362e66896bb5d970c8f4cf\ 0875a160cc5b612189d8ffa64b0ffd93efdf4d21ef996908a764a4ec8c00a3ce\ 90adb38e9c2c4aacbfb2957f7a8207db1b2a586ea2c8938982549e744e56086e\ f2053233c540f559f0bce03be1c5f1c18d791c3681a26391796017114b2b35f9\ 199e8fff11a25f5d3f06d1aec79d08131f022d1c2fa541e6476e59cf6c514333\ 1cb807016cb07' }, / ciphertext / h'934bb9f49942192bea7a56a9f52f2070a2ded7eaebaddb44b\ cd5335c743a7b5fc84fa37b3643bc66e8863b0fc560a1615ada8570b64497f8a\ afb73bd44f280d92ce6f55c9afa535337c43fc422927cbc0e46683b946701c11\ e889d4bee35fd7c9ef335def2edd594c5a5fdeda6ea9478d0fb93abe2ed4c8cb\ 9c8af87dfbb9c2a095cf9a4fdfecd4e0ea307205b1a8408e9676fb91a1ee3db6\ fce27b73366f590ad47546aefef17dd144a2cde568a08b5072fa2a144fe8d784\ 07a70ceb6704a01d76fa4d8dc45ef3adbb1cfa1ee59791b81f88e4c81b15b39b\ b892c53cb339d3205a45c96da5a1e0c2511b7436a38c9c12565fa057c962395c\ c15ceadc8b6c4720a445ddefbcb18d9c36fd6c0d5ce584cacd80c1f6b40cd2e5\ e6082e5db579140b3' ]) Figure 27: HPKE-11 COSE_Encrypt0 (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 50] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 d08344a101183ca2045820400faa06149080d620fa067cabef42e03b05a7705da721\ 88cd2732e034e493dc235903008e6c3c2040aadc5e88394e9f8e64459062d0ae76c9\ 41e7e4a20158310056e59cacd8a62ba1569fe2e9b4495c61201afac15702398412e4\ e92c9dfb098ef00ea417a67235b9b4582c83efb1fe47a8d77143d322618aab4960ca\ 6ff3bc6e0b0a3a891620f21eb9f877253ae8768d5beb72683ee9d54c375e06a6e460\ fe963f47aa7950fb246b3432cc75e2b86421363a324fd2baddbbdefa71de7f304a6c\ 1aad4e4e0bac4e62daffa1fa05605065d4bdcfab842b2777a35f69eacc452037b0ef\ b4c6d7f1522b31e19a5f8d06c10ba42803ab58b4c6106d5c98f88872256fce8d1e78\ 58b9020ffa8243a617077fc51f90dc939ff42ce3cccd62a64ad3e45e4d2cadf13539\ 22c73fa503369ea34b9cbbb5b20b2c69b88a5f7fa07c41c820a1fc0cfc8b702f6740\ 7bb1e5c8beecce96b5c925c564cbaebbf874cc60b65ae469e9a28c859220ed373293\ 3891963566a4d4ff744f0716be4fb7b40015d00e138b552500f804a68393086d2593\ 18e9dbc2cc17ec3d4d32b3890e31cca17eb6cca9f36d6cfb7274fc8cd4d8dcdd0b20\ fa4e609a5e17a7c60293c308bb00c5abc63fee3f811bac44a39b6175854bf7b92312\ 0edd2ab52d3052a373f1762e7cc0fee18f550a30667a2054fddb4d498a96407b2826\ 71d4e650189fe7544a232eb9bcab0d28dda0e523fad70d5bbad428de286e1c7e4f77\ 4a125ba577daa0ae129cd17a40746e484f88c1debdd2101d4cd6becf08cd0a2574ae\ c253045dd4e0e2e21b7c3da70b07712725299a48db218189f7daae5250c22cde5237\ e64efe366ddedd519098de1ccad4a55a1d0a5fd6760b16839d3bb887b3eedd3459c1\ 62779129cf62941dc04fae9ae494ded2cad4f082be84bbd362e66896bb5d970c8f4c\ f0875a160cc5b612189d8ffa64b0ffd93efdf4d21ef996908a764a4ec8c00a3ce90a\ db38e9c2c4aacbfb2957f7a8207db1b2a586ea2c8938982549e744e56086ef205323\ 3c540f559f0bce03be1c5f1c18d791c3681a26391796017114b2b35f9199e8fff11a\ 25f5d3f06d1aec79d08131f022d1c2fa541e6476e59cf6c5143331cb807016cb0759\ 0121934bb9f49942192bea7a56a9f52f2070a2ded7eaebaddb44bcd5335c743a7b5f\ c84fa37b3643bc66e8863b0fc560a1615ada8570b64497f8aafb73bd44f280d92ce6\ f55c9afa535337c43fc422927cbc0e46683b946701c11e889d4bee35fd7c9ef335de\ f2edd594c5a5fdeda6ea9478d0fb93abe2ed4c8cb9c8af87dfbb9c2a095cf9a4fdfe\ cd4e0ea307205b1a8408e9676fb91a1ee3db6fce27b73366f590ad47546aefef17dd\ 144a2cde568a08b5072fa2a144fe8d78407a70ceb6704a01d76fa4d8dc45ef3adbb1\ cfa1ee59791b81f88e4c81b15b39bb892c53cb339d3205a45c96da5a1e0c2511b743\ 6a38c9c12565fa057c962395cc15ceadc8b6c4720a445ddefbcb18d9c36fd6c0d5ce\ 584cacd80c1f6b40cd2e5e6082e5db579140b3 Figure 28: HPKE-11 COSE_Encrypt0 (Hex-Encoded CBOR) A.8. HPKE-11-KE Reddy, et al. Expires 14 November 2026 [Page 51] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'66b4942df6e05b245389a93dcc1303ac63a692f4ea92b2cb62c1c\ d191a7751f0', / alg / 3: 61 / HPKE-11-KE /, / pub / -1: h'bdda40b91285e7e4c2106c1e8ad834817816ac961ed7fc13ca6a\ ad917b3d3f01345cba4a01a8acabc39e5fb18d13c9bf91a071ec78b2564831e6\ 1613c58931f0a079790a0bd097099f8ca00627c5abaac4cb03460c9991baea35\ 7f007fa0bb937fe47f8ac42e165452093c61bcc3616b39c105d4a0229c099d1b\ 4104b61d99856bcba90bae76c418fa8c7d35c0fe604404122af3c6556116b394\ eb2c6f2076d3098017a24fed82433b9181d09c76dd319aa95a3ba0a02a509679\ 89f0090088acb4ac6f44ebae51bba5cddb2da3a013dd28caa2304a630ba32854\ 437fea97fe712921cc524636b6b5955129ab8e813b50f420741ed30a0df47970\ 842d0b5222f2450ab862213567a0cc2b83507c71cec909d4e1559873c4ac6c1d\ 68a7971ca7a032421279d061ef4356da81983a9a0f3e7b9639214d3467b8d7f8\ 3f729843311038213ac61b80a5726106491c779a83c5ca0447b7fa95c3cab3f3\ 961e66845efa6993db976eb69149bfc5b6970510e6aba20759396610c8bd5705\ cb75ae53c735f9873834399511471b0ca11626682ddac33515009ed8311d97bb\ 2a35a6c4ce34717cfc68d4a427f758c6a7276fa60987b0615e343a6b7d3b91ef\ e728886694243ca52c989fdb45328da161ebc9cc2a1bcf019b741695544cb637\ 48c03a5e23bc7101678ad49b3bb440a1675b14db8c4bd532068733703c7b3753\ 6a033b484fe28a4590b630a7cb9128248a65052631c827a4c621c446d336bb99\ e7b96d4b879c291a3c123b5fd66664726e479c99161a756a269eb7fb3827527f\ 8a539e5e556e78588037823aa1d61939b6230691ce6cf16215b6a85da8ae45e0\ 8362209413c927b6e914af7645bd0c503f90c137f5626bf1ce5ca55a951b0eb2\ 837bd46817854a198145a96b9172983783276c11aa703b1b7030bb0576997b8b\ 8d357708a9b5f8b311ea2aa3909696dec9a8b7a49bcdb553dec8952d724f20d8\ 9790d101014c3c08e35decf201dcf9b23ed43b8cb4c10b455c27a54b47661a64\ 8304a9d83572386b2d135456ca33bda631de586ae9008fd7c465d2bc79de8a1a\ 8ab55c5318818fad5f369b21b1ece6c7d52af1c6a1f08cc5df299abcd2c996dd\ ba296065465b', / priv / -2: h'6206c57ba5f678eb6d06ac44d428ed461701f48d7b2ed06c8f6\ 4f25cb72cf9a59afeea9c511fcf152c7760e1fea926431880974236eaa9f36dd\ 83a4cd871888b' } Figure 29: HPKE-11-KE COSE_Key (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 52] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 a5010702582066b4942df6e05b245389a93dcc1303ac63a692f4ea92b2cb62c1cd19\ 1a7751f003183d20590320bdda40b91285e7e4c2106c1e8ad834817816ac961ed7fc\ 13ca6aad917b3d3f01345cba4a01a8acabc39e5fb18d13c9bf91a071ec78b2564831\ e61613c58931f0a079790a0bd097099f8ca00627c5abaac4cb03460c9991baea357f\ 007fa0bb937fe47f8ac42e165452093c61bcc3616b39c105d4a0229c099d1b4104b6\ 1d99856bcba90bae76c418fa8c7d35c0fe604404122af3c6556116b394eb2c6f2076\ d3098017a24fed82433b9181d09c76dd319aa95a3ba0a02a50967989f0090088acb4\ ac6f44ebae51bba5cddb2da3a013dd28caa2304a630ba32854437fea97fe712921cc\ 524636b6b5955129ab8e813b50f420741ed30a0df47970842d0b5222f2450ab86221\ 3567a0cc2b83507c71cec909d4e1559873c4ac6c1d68a7971ca7a032421279d061ef\ 4356da81983a9a0f3e7b9639214d3467b8d7f83f729843311038213ac61b80a57261\ 06491c779a83c5ca0447b7fa95c3cab3f3961e66845efa6993db976eb69149bfc5b6\ 970510e6aba20759396610c8bd5705cb75ae53c735f9873834399511471b0ca11626\ 682ddac33515009ed8311d97bb2a35a6c4ce34717cfc68d4a427f758c6a7276fa609\ 87b0615e343a6b7d3b91efe728886694243ca52c989fdb45328da161ebc9cc2a1bcf\ 019b741695544cb63748c03a5e23bc7101678ad49b3bb440a1675b14db8c4bd53206\ 8733703c7b37536a033b484fe28a4590b630a7cb9128248a65052631c827a4c621c4\ 46d336bb99e7b96d4b879c291a3c123b5fd66664726e479c99161a756a269eb7fb38\ 27527f8a539e5e556e78588037823aa1d61939b6230691ce6cf16215b6a85da8ae45\ e08362209413c927b6e914af7645bd0c503f90c137f5626bf1ce5ca55a951b0eb283\ 7bd46817854a198145a96b9172983783276c11aa703b1b7030bb0576997b8b8d3577\ 08a9b5f8b311ea2aa3909696dec9a8b7a49bcdb553dec8952d724f20d89790d10101\ 4c3c08e35decf201dcf9b23ed43b8cb4c10b455c27a54b47661a648304a9d8357238\ 6b2d135456ca33bda631de586ae9008fd7c465d2bc79de8a1a8ab55c5318818fad5f\ 369b21b1ece6c7d52af1c6a1f08cc5df299abcd2c996ddba296065465b2158406206\ c57ba5f678eb6d06ac44d428ed461701f48d7b2ed06c8f64f25cb72cf9a59afeea9c\ 511fcf152c7760e1fea926431880974236eaa9f36dd83a4cd871888b Figure 30: HPKE-11-KE COSE_Key (Hex-Encoded CBOR) NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt / 96([ / protected / h'a10101', / unprotected / { / iv / 5: h'0aab0d623e3ade196aaf572b' }, / ciphertext / h'cade8e5050387bff05b73e1d021e368978103becabbe5f52a\ cb2a2618e1f1e75fa422e018846784975323e6df2f410fbd512a1ae4814ce83d\ ca6f3646ccee64d6e415a0978bcd42e307d7ee711cb2cb38591c9ca62b61f211\ f7da7c8d4e5a59ed978815aedf10dfb05abb7afaf283d11ca81ee6f9fd52b0e2\ 4dc7fadc0313c2a66e31d766002680c940f90d4d3c365a4f89f6d4c0bde503de\ 012c1ab22cac3a690f4cf9682430a6b386cadf93e71e908ad369cdcfb1d1e9ec\ 06e5208a7bb423534ae95ec6e28c204228ee8ada8c3cd28957c7cfb99d51aa2a\ 10125c047f5a094faeeb0f60c19aab9ab23cbb71d9d8c146b04bc88ce1a74366\ 8509d839df106f21e2f958c8f2a69c0d8f8122d9bdbc44b3bf370b44f3859cde\ Reddy, et al. Expires 14 November 2026 [Page 53] Internet-Draft COSE HPKE PQ May 2026 4db01bf5a20813eb4', / recipients / [ [ / protected / h'a201183d04582066b4942df6e05b245389a93dcc1303ac\ 63a692f4ea92b2cb62c1cd191a7751f0', / unprotected / { / ek / -4: h'089da49105ce8802dcdb0629fb6f759a18528ec91ea1f41\ afdaa4e56a15d3c01cf5105e5f16255aea6daa7b9ba145edaae3a7f868b53ce2\ 38a2f071495b7c7b82c503fbc2d1b1ffaaca3dd76e81f2030da5c5a3b6417a36\ 3e4ae2985302565825becd6b4b9a0e821bbcad2f9e872e9c09981c6af8238ce0\ f32a3d7eca23127eba7086f72b008498237527a3089d033b10528d8b74a88050\ 7fddfd63bc43db80365c9dd5c5dd4063e186ea01c8344697b093856708ad3b06\ db0cfd310051c8eb97bd83fdb81fba3e49ca74532697cf9a5cdf858d6c5d2000\ 5ab61ed2fc10ed8af811bc19ade46f00586c09108dbf8c0a3caaa155614be58d\ 4b3289cebba34f120c934d339cccc7a9fe45e1b20cd13511508569775a0a53dd\ 12ee7570ce49213ff4f10685da97a2544ca8203082a8cf31a85a036739ed613d\ c82c4ce0aef9fc3f1d6610ef8c77121efafc1c7bced3a4830a68da73b48c7e86\ 3353250645ae550b810b3b60dced2677f4b1385213cfd842362abfc19ebd097d\ dd9adbd08bcc754bad9f264f266fc2a6400cbbcb499589a40e8c9cb2b64a47ac\ 61480c75096cfdea8bb62479f6451c956ab5f27d97aa2efd94139444f59d9426\ ebfd3bec8e48f42b8f206810453570b5de626bd7c100494329e24c7e65d52eae\ ff933a88a742400a2d5e58d36cb87a1c87e6a8a753665491dcfb94d8e25b14dd\ aacef28d79a194d336ee9abc15cd50ba90905ecacb37e52a5401799980f94069\ c4f4c622fb7d3ad6611b764703c08382cf512ce4ec3187e11789f3cccd452497\ 4a12ef73b231aa34d920394bf34be6c8f71dbb250039da1d5f8853f9c51562b7\ 1b164f8885b9b85c6adf427fbed5d2921a93d87e155c95412549d98673182946\ 077485300089b3b09b0501d7207b4810d11ac835cc90c6ce6560fb53131b2708\ af3f7cd500bad364c3917660b0072debfebfe69a2b1c4a05921bb6d8defad807\ 87875fd42765e66ea7a9374f01024f4b110686809805e3dd341795a0e322eda4\ 39c728d47c17029f1af393a08f22fdb423346ae9cdf67779df91676e6b5a3a2d\ 0b39f451dccad9f82' }, / ciphertext / h'011bea833595a8ce3a0c1b2434dc841c245451bed09f3\ 26299b0f8012c234124' ] ] ]) Figure 31: HPKE-11-KE COSE_Encrypt (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 54] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 d8608443a10101a1054c0aab0d623e3ade196aaf572b590121cade8e5050387bff05\ b73e1d021e368978103becabbe5f52acb2a2618e1f1e75fa422e018846784975323e\ 6df2f410fbd512a1ae4814ce83dca6f3646ccee64d6e415a0978bcd42e307d7ee711\ cb2cb38591c9ca62b61f211f7da7c8d4e5a59ed978815aedf10dfb05abb7afaf283d\ 11ca81ee6f9fd52b0e24dc7fadc0313c2a66e31d766002680c940f90d4d3c365a4f8\ 9f6d4c0bde503de012c1ab22cac3a690f4cf9682430a6b386cadf93e71e908ad369c\ dcfb1d1e9ec06e5208a7bb423534ae95ec6e28c204228ee8ada8c3cd28957c7cfb99\ d51aa2a10125c047f5a094faeeb0f60c19aab9ab23cbb71d9d8c146b04bc88ce1a74\ 3668509d839df106f21e2f958c8f2a69c0d8f8122d9bdbc44b3bf370b44f3859cde4\ db01bf5a20813eb481835827a201183d04582066b4942df6e05b245389a93dcc1303\ ac63a692f4ea92b2cb62c1cd191a7751f0a123590300089da49105ce8802dcdb0629\ fb6f759a18528ec91ea1f41afdaa4e56a15d3c01cf5105e5f16255aea6daa7b9ba14\ 5edaae3a7f868b53ce238a2f071495b7c7b82c503fbc2d1b1ffaaca3dd76e81f2030\ da5c5a3b6417a363e4ae2985302565825becd6b4b9a0e821bbcad2f9e872e9c09981\ c6af8238ce0f32a3d7eca23127eba7086f72b008498237527a3089d033b10528d8b7\ 4a880507fddfd63bc43db80365c9dd5c5dd4063e186ea01c8344697b093856708ad3\ b06db0cfd310051c8eb97bd83fdb81fba3e49ca74532697cf9a5cdf858d6c5d20005\ ab61ed2fc10ed8af811bc19ade46f00586c09108dbf8c0a3caaa155614be58d4b328\ 9cebba34f120c934d339cccc7a9fe45e1b20cd13511508569775a0a53dd12ee7570c\ e49213ff4f10685da97a2544ca8203082a8cf31a85a036739ed613dc82c4ce0aef9f\ c3f1d6610ef8c77121efafc1c7bced3a4830a68da73b48c7e863353250645ae550b8\ 10b3b60dced2677f4b1385213cfd842362abfc19ebd097ddd9adbd08bcc754bad9f2\ 64f266fc2a6400cbbcb499589a40e8c9cb2b64a47ac61480c75096cfdea8bb62479f\ 6451c956ab5f27d97aa2efd94139444f59d9426ebfd3bec8e48f42b8f20681045357\ 0b5de626bd7c100494329e24c7e65d52eaeff933a88a742400a2d5e58d36cb87a1c8\ 7e6a8a753665491dcfb94d8e25b14ddaacef28d79a194d336ee9abc15cd50ba90905\ ecacb37e52a5401799980f94069c4f4c622fb7d3ad6611b764703c08382cf512ce4e\ c3187e11789f3cccd4524974a12ef73b231aa34d920394bf34be6c8f71dbb250039d\ a1d5f8853f9c51562b71b164f8885b9b85c6adf427fbed5d2921a93d87e155c95412\ 549d98673182946077485300089b3b09b0501d7207b4810d11ac835cc90c6ce6560f\ b53131b2708af3f7cd500bad364c3917660b0072debfebfe69a2b1c4a05921bb6d8d\ efad80787875fd42765e66ea7a9374f01024f4b110686809805e3dd341795a0e322e\ da439c728d47c17029f1af393a08f22fdb423346ae9cdf67779df91676e6b5a3a2d0\ b39f451dccad9f825820011bea833595a8ce3a0c1b2434dc841c245451bed09f3262\ 99b0f8012c234124 Figure 32: HPKE-11-KE COSE_Encrypt (Hex-Encoded CBOR) A.9. HPKE-12 NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'6af47f413f10204703b2f48ba4c8d69b5a41148d36a47c7f49726\ 1757a8a0dcc', Reddy, et al. Expires 14 November 2026 [Page 55] Internet-Draft COSE HPKE PQ May 2026 / alg / 3: 62 / HPKE-12 /, / pub / -1: h'd9d98bc2e3bff7e7a9b6277829385e3c184a1c505d3b054f73c9\ 4d8db79218b3a615d9b3477c83ffe66e71982b487a9a70d543fe8112d99092f4\ 211e150c8d818431ac145bd6043c2580bd3e688d15675b37e7a2c52696b1868b\ 4f07a40a2b9cc0e86c4b04aeb1180cb74222d83c8a97a9b62757c38030827af5\ 617bc208d00c66d8968965a3607ed53da4b13c43000a63db5fa2dc77c334115d\ d13ad6b99c11039f210889afa4c6f984a5fdc111c5bb0916bc87d609ae816923\ 7053a37bd3528997cb6b69a2ff4b3a307a640108719b61156827c733c7ccb02a\ 6406a28e80f4ca9021931b403a4672a003b49c9578bc3fc909ba9c78e8a9b7b9\ e47a284185d91b41b7a4a616471eba3677a16b7b4e8aad7354818c538d934191\ b99001662b22521a9733d23f4fbc9a80b85d42a3afb2b21596509f14e1478898\ 4f1443cb380332414ac28fb77557c87e72b021ca9890610145a92ab7d3da1e46\ a606547c8f2c47b99bf96f7f17c53128ad45c16b99c84ed8e4426d94139beb62\ a32b25bba50d0f06166ab47452680920f95f34b27df1734ee4b3b77e38b3f388\ 470b49cb9ceaa60ff3b89161035e40423d6b3f9b3a269592a7719762403197b2\ e70c51486cfb24a8fdaaac96cc2e99f938e46b0ffe9523e7544e715aa08f3092\ c9db6468a3769e4a25b9b1afe26bcd01a733f7da0b28bcc36ea008aa845301b1\ 80255cb036906ecc5c3fda01a2a9289db6b52608972e6a2867a0007e765a422e\ 070d51301327546d0a549b5e9196f57250f5c434d375307d5229f28c3112c16a\ 8241c48d1b038c927db2292af40692ce827aabe99049173270068cf8e7706a88\ 45b2b104b55459d3b0bc51a85e944326676aad10c107a6410188d010f7997a98\ 18cb15d5c62a83af048bbda2c8586b71bfada04ee2b83a17890a9213b4874bbb\ bac282f2659079d7c9dd6b409a988dc0d27109d4518ed762823a156d13242265\ 6f26169a2362914370189de59c01b46b6b7698dd290a8e43213d9a76355ab277\ 75c350d0221601c339fbc93053a4cfe56059395f3337b6cfcc37c0f52d6698c7\ e1b414b57b25995c541b08b5fc3bbaa87ca29fdc4f3bc4afe9e34aaad856f58c\ 188818c4efd007349631ee743adc833d1bd46d17719b590b4ff64c9ed7a5a1a3\ 9b198bd93ef4184ec70c172de8aa1cec0f445306c90139c9277d84e51268d19a\ 8d5599cad58e9a9b7c452acb9d76389a8c402991067e12056083954489a3b4b1\ 9e10165f4725526307cf2c99c7e520c10629a896dc35521c771d004e77a166b8\ 6b1156262efd47ca0f12ac7008090741584ba172a0ac487a49cf1e9a30949749\ 75ba4c17d40817698dca775d1447c624762575f071c87402209696c47c054df6\ 317a22abb6e727ac29a6db0056237c27b5452b0b9775bc698b23faba55c779b1\ 78959b966f10d75dacf7889c668b614823e8d9791e23215e3a7bb7694b31134d\ b64a28991c74520c2c810271e8b102ebfb341ba1389d77b9d9455d91fb10ccaa\ 41edd99ac52916586ba99a0741717a725fdcaa603a99885caede96c7a3b54400\ 2d0ba753b26b5a423fa90e34966e0c646c710ace6c8b81999c338f807f0b049e\ bba667278418091dfbe0b946e151cc5fd848c3b4beb69d63d1065bde88e69dae\ bb43274eb7e3', / priv / -2: h'a0dad96b56dd010b716e9dbac3999c660cf0edf291d16c446e9\ 461547e6d70f450c73224dc88aab7aa7d167f3ca636286949a695a3729ae4e4f\ f0b355a059dda' } Figure 33: HPKE-12 COSE_Key (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 56] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 a501070258206af47f413f10204703b2f48ba4c8d69b5a41148d36a47c7f49726175\ 7a8a0dcc03183e205904a0d9d98bc2e3bff7e7a9b6277829385e3c184a1c505d3b05\ 4f73c94d8db79218b3a615d9b3477c83ffe66e71982b487a9a70d543fe8112d99092\ f4211e150c8d818431ac145bd6043c2580bd3e688d15675b37e7a2c52696b1868b4f\ 07a40a2b9cc0e86c4b04aeb1180cb74222d83c8a97a9b62757c38030827af5617bc2\ 08d00c66d8968965a3607ed53da4b13c43000a63db5fa2dc77c334115dd13ad6b99c\ 11039f210889afa4c6f984a5fdc111c5bb0916bc87d609ae8169237053a37bd35289\ 97cb6b69a2ff4b3a307a640108719b61156827c733c7ccb02a6406a28e80f4ca9021\ 931b403a4672a003b49c9578bc3fc909ba9c78e8a9b7b9e47a284185d91b41b7a4a6\ 16471eba3677a16b7b4e8aad7354818c538d934191b99001662b22521a9733d23f4f\ bc9a80b85d42a3afb2b21596509f14e14788984f1443cb380332414ac28fb77557c8\ 7e72b021ca9890610145a92ab7d3da1e46a606547c8f2c47b99bf96f7f17c53128ad\ 45c16b99c84ed8e4426d94139beb62a32b25bba50d0f06166ab47452680920f95f34\ b27df1734ee4b3b77e38b3f388470b49cb9ceaa60ff3b89161035e40423d6b3f9b3a\ 269592a7719762403197b2e70c51486cfb24a8fdaaac96cc2e99f938e46b0ffe9523\ e7544e715aa08f3092c9db6468a3769e4a25b9b1afe26bcd01a733f7da0b28bcc36e\ a008aa845301b180255cb036906ecc5c3fda01a2a9289db6b52608972e6a2867a000\ 7e765a422e070d51301327546d0a549b5e9196f57250f5c434d375307d5229f28c31\ 12c16a8241c48d1b038c927db2292af40692ce827aabe99049173270068cf8e7706a\ 8845b2b104b55459d3b0bc51a85e944326676aad10c107a6410188d010f7997a9818\ cb15d5c62a83af048bbda2c8586b71bfada04ee2b83a17890a9213b4874bbbbac282\ f2659079d7c9dd6b409a988dc0d27109d4518ed762823a156d132422656f26169a23\ 62914370189de59c01b46b6b7698dd290a8e43213d9a76355ab27775c350d0221601\ c339fbc93053a4cfe56059395f3337b6cfcc37c0f52d6698c7e1b414b57b25995c54\ 1b08b5fc3bbaa87ca29fdc4f3bc4afe9e34aaad856f58c188818c4efd007349631ee\ 743adc833d1bd46d17719b590b4ff64c9ed7a5a1a39b198bd93ef4184ec70c172de8\ aa1cec0f445306c90139c9277d84e51268d19a8d5599cad58e9a9b7c452acb9d7638\ 9a8c402991067e12056083954489a3b4b19e10165f4725526307cf2c99c7e520c106\ 29a896dc35521c771d004e77a166b86b1156262efd47ca0f12ac7008090741584ba1\ 72a0ac487a49cf1e9a3094974975ba4c17d40817698dca775d1447c624762575f071\ c87402209696c47c054df6317a22abb6e727ac29a6db0056237c27b5452b0b9775bc\ 698b23faba55c779b178959b966f10d75dacf7889c668b614823e8d9791e23215e3a\ 7bb7694b31134db64a28991c74520c2c810271e8b102ebfb341ba1389d77b9d9455d\ 91fb10ccaa41edd99ac52916586ba99a0741717a725fdcaa603a99885caede96c7a3\ b544002d0ba753b26b5a423fa90e34966e0c646c710ace6c8b81999c338f807f0b04\ 9ebba667278418091dfbe0b946e151cc5fd848c3b4beb69d63d1065bde88e69daebb\ 43274eb7e3215840a0dad96b56dd010b716e9dbac3999c660cf0edf291d16c446e94\ 61547e6d70f450c73224dc88aab7aa7d167f3ca636286949a695a3729ae4e4ff0b35\ 5a059dda Figure 34: HPKE-12 COSE_Key (Hex-Encoded CBOR) Reddy, et al. Expires 14 November 2026 [Page 57] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt0 / 16([ / protected / h'a101183e', / unprotected / { / kid / 4: h'6af47f413f10204703b2f48ba4c8d69b5a41148d36a47c7f497\ 261757a8a0dcc', / ek / -4: h'2ce85d7e6308f65d42e8464f86a5ece10df9f3bb2d523531f64\ 8b5849783d109175d632a7b8e20fc5d22929c9df78ab2c9d94ee56efe6dc2056\ 36684ef6cadc4cb66edbb56abe7775842c5f4e90d525f709e82270af4981ebce\ 6dc2f7faae61f7ff1f4908b7b19006c6e1480ad38226276efd60d81e3a3fc4f1\ 7f52102af8d9feccc008199291f74a58902d94124cd8cc3dd1f9e31658297991\ 97d2ef503213a7fc54e6831c481686802b23ac30a1191dc7a3ff70490dad8164\ 8ceba9787e874f57b2bc63b005bb5aedd72b52390867e3a8ba61a0e9bdd33c6a\ f95b8f4ab01e32d87fd53a5e5cac1703797bc12ed82fe9109293cb4030357109\ a57eeb27c8633802449c6f8fba98fb492fde0ca81e3fe06d6cd67f3eb845bbde\ 34c837e9e499e864bf9f3459ea776a85e0621a8aceb0b9f2dafec5e28199f981\ 217ccb1ab3eb2cb5146232395c99e8ddb5842c8a83e9192365cbbcda226886fe\ f36a11c8eaf2a3fa92ff872984febad97bf8e2f356d7bb494cefa2f904010818\ 559414ad992c17e801a93f7b36125ea73cd17ff1019dcd0b1367f1332a178ca7\ bbc06fed0ac7f133ce3b63126e829f4b18db709e8373099b0cd3edbebef1df48\ 955bcfa7c142b46d951cdf02689ada8ad4bc64481f2f27b19e5e5b01c89854ce\ 9bb0f84e095235b2983d46e758464f0e7b91c819d7fe8c75c595eb8ffb8e90bc\ 982f0420a395c0399f7fbd6530c194072068014dea9a41df748f2d871e55eb47\ 2b7c81500164302a716148f667a132d69ed90f6f4a40a32ce674890761a35701\ 39c69406b6b5b382e1284d4b1f92eda241547793d6fc7bc680b700fbd65b7c7f\ 4be8d0a53dc7b68987ffb47d6dff01e663034cb47e8a1c320148ae7a2451d556\ 020a010bb34991942766b4b5ce44395bde79a6b82a57de39a20ee076aaf4f642\ 90d734f04620b5f8acc5bcf2b3e01262315722bc32eb07b93afbd1e26d2a62ec\ 6c34249e822ba344dd2898378d205e5f240df0ea45513811f3b22cc17e8f6c88\ 0157cfd7fe141f0701fbefa2e5a7d7f07854ef6a8707072a43f85e605dbe4f41\ 450c147a78d40814defb5fd0766353b21ddecf032c0d7a644067d11979d9ed98\ 93b7ec989d4f4e3a518b3042ba0bb14e9764da68f6981b2c63e56a23a8ea6174\ f6b059d0fe74e2625c4dd932d2dbb12fdb4fb7834e3b6a6b8f152c14ad488a71\ dc6225eb5aac9bb7e67bae2c09de0428a41655f095b15fd1872dd51e5be306f5\ 15737e8e431c22d7e8c0ce4598fda7f050cad02999f0dbe47af810b29240d0b1\ 17dd412900d372a5b82d0f42f5e998dfb861b254798cbb007b68230c685316dc\ 5a141fb2c2c82a362c5ca1429c05a25f5a22954228376af6e9e6f198c24e8597\ 98ccec85cd295f196bf493cc8a1927964baf379ea8eb3597ed048eb91715efa1\ be0a93be4ff56ed4bfe4017099c1ce1bcd15461fa62a3eff4d402c7ebf624acd\ 7fe4d74a74e32c9627f99424fd903002788319d9677ce52a3c9c0d7988c0b6d4\ 388bd7a67712e' }, / ciphertext / h'80480620adaaf2d3ee5fbda6219e8e7f1a9d086d0a1b11335\ 995b11d68518bfaa15765eaed343d2ec7dfecef907e19851e27d25d21ee4bc23\ 542a17afa09734305abfec9a872bfbf3fff1608577cf84d78d49ef339644d4ac\ dd09167e5ff71171d0b08f974567ffd03d3f3bcfd38f1610eeddd91401684f8f\ 71d529d7525e53f2f31cd70aa6e287e2ac3bd5bf76af19236e78760912348985\ Reddy, et al. Expires 14 November 2026 [Page 58] Internet-Draft COSE HPKE PQ May 2026 d191e839e3518daf8ac7c12d1fb0276dd7244aa83bff12147c403873f15213fb\ 0d3fb2001b3e6b83226298f663f262f7521e516ae3d02a029c0dae7df73e5837\ 1504d48edddfbf68d74fec4f1b65a9ab319b60c90e62aa7f316533555774514e\ 5302651177ae0b6c794707aaa3ba13f5c0e21d595251c8d84973f762ce3f5d56\ e2162e2b5094052e1' ]) Figure 35: HPKE-12 COSE_Encrypt0 (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 59] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 d08344a101183ea20458206af47f413f10204703b2f48ba4c8d69b5a41148d36a47c\ 7f497261757a8a0dcc235904402ce85d7e6308f65d42e8464f86a5ece10df9f3bb2d\ 523531f648b5849783d109175d632a7b8e20fc5d22929c9df78ab2c9d94ee56efe6d\ c205636684ef6cadc4cb66edbb56abe7775842c5f4e90d525f709e82270af4981ebc\ e6dc2f7faae61f7ff1f4908b7b19006c6e1480ad38226276efd60d81e3a3fc4f17f5\ 2102af8d9feccc008199291f74a58902d94124cd8cc3dd1f9e3165829799197d2ef5\ 03213a7fc54e6831c481686802b23ac30a1191dc7a3ff70490dad81648ceba9787e8\ 74f57b2bc63b005bb5aedd72b52390867e3a8ba61a0e9bdd33c6af95b8f4ab01e32d\ 87fd53a5e5cac1703797bc12ed82fe9109293cb4030357109a57eeb27c8633802449\ c6f8fba98fb492fde0ca81e3fe06d6cd67f3eb845bbde34c837e9e499e864bf9f345\ 9ea776a85e0621a8aceb0b9f2dafec5e28199f981217ccb1ab3eb2cb5146232395c9\ 9e8ddb5842c8a83e9192365cbbcda226886fef36a11c8eaf2a3fa92ff872984febad\ 97bf8e2f356d7bb494cefa2f904010818559414ad992c17e801a93f7b36125ea73cd\ 17ff1019dcd0b1367f1332a178ca7bbc06fed0ac7f133ce3b63126e829f4b18db709\ e8373099b0cd3edbebef1df48955bcfa7c142b46d951cdf02689ada8ad4bc64481f2\ f27b19e5e5b01c89854ce9bb0f84e095235b2983d46e758464f0e7b91c819d7fe8c7\ 5c595eb8ffb8e90bc982f0420a395c0399f7fbd6530c194072068014dea9a41df748\ f2d871e55eb472b7c81500164302a716148f667a132d69ed90f6f4a40a32ce674890\ 761a3570139c69406b6b5b382e1284d4b1f92eda241547793d6fc7bc680b700fbd65\ b7c7f4be8d0a53dc7b68987ffb47d6dff01e663034cb47e8a1c320148ae7a2451d55\ 6020a010bb34991942766b4b5ce44395bde79a6b82a57de39a20ee076aaf4f64290d\ 734f04620b5f8acc5bcf2b3e01262315722bc32eb07b93afbd1e26d2a62ec6c34249\ e822ba344dd2898378d205e5f240df0ea45513811f3b22cc17e8f6c880157cfd7fe1\ 41f0701fbefa2e5a7d7f07854ef6a8707072a43f85e605dbe4f41450c147a78d4081\ 4defb5fd0766353b21ddecf032c0d7a644067d11979d9ed9893b7ec989d4f4e3a518\ b3042ba0bb14e9764da68f6981b2c63e56a23a8ea6174f6b059d0fe74e2625c4dd93\ 2d2dbb12fdb4fb7834e3b6a6b8f152c14ad488a71dc6225eb5aac9bb7e67bae2c09d\ e0428a41655f095b15fd1872dd51e5be306f515737e8e431c22d7e8c0ce4598fda7f\ 050cad02999f0dbe47af810b29240d0b117dd412900d372a5b82d0f42f5e998dfb86\ 1b254798cbb007b68230c685316dc5a141fb2c2c82a362c5ca1429c05a25f5a22954\ 228376af6e9e6f198c24e859798ccec85cd295f196bf493cc8a1927964baf379ea8e\ b3597ed048eb91715efa1be0a93be4ff56ed4bfe4017099c1ce1bcd15461fa62a3ef\ f4d402c7ebf624acd7fe4d74a74e32c9627f99424fd903002788319d9677ce52a3c9\ c0d7988c0b6d4388bd7a67712e59012180480620adaaf2d3ee5fbda6219e8e7f1a9d\ 086d0a1b11335995b11d68518bfaa15765eaed343d2ec7dfecef907e19851e27d25d\ 21ee4bc23542a17afa09734305abfec9a872bfbf3fff1608577cf84d78d49ef33964\ 4d4acdd09167e5ff71171d0b08f974567ffd03d3f3bcfd38f1610eeddd91401684f8\ f71d529d7525e53f2f31cd70aa6e287e2ac3bd5bf76af19236e78760912348985d19\ 1e839e3518daf8ac7c12d1fb0276dd7244aa83bff12147c403873f15213fb0d3fb20\ 01b3e6b83226298f663f262f7521e516ae3d02a029c0dae7df73e58371504d48eddd\ fbf68d74fec4f1b65a9ab319b60c90e62aa7f316533555774514e5302651177ae0b6\ c794707aaa3ba13f5c0e21d595251c8d84973f762ce3f5d56e2162e2b5094052e1 Figure 36: HPKE-12 COSE_Encrypt0 (Hex-Encoded CBOR) Reddy, et al. Expires 14 November 2026 [Page 60] Internet-Draft COSE HPKE PQ May 2026 A.10. HPKE-12-KE NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'da3c1ad21455112a22a022e2a9f3738002fc448ca06f10222076f\ 8e24cb37c88', / alg / 3: 63 / HPKE-12-KE /, / pub / -1: h'1f3a20ac944450f00eb8456a6be0cffed5733a322f4373c10f0a\ 333192be2e7421b7f9a3604a61ba09958c5ab622c19f17d7cad937af40342f9d\ 0287a04467485ccfe3b681c5706309902891d57fc3a948fe396b64b366127716\ ecac90a59564aeb75002b60b891431964a330fb15a5e5504ebfc940981703858\ a70b455b7fbb43a99c06a2b759a02c215f0746cd4a94e473c794477355397e36\ d19076863437b136ce260aabd0b413d412b2dc980812aa77fa96483c264c1889\ 46a8cd857793b787ba0c42363b12b6e4a2b1adf61dea4a47605a59602c2d7c66\ 05ea3596363a52595717b83c74c4b728f0c81593970def696fbd5960d9f0c138\ b7b1180c0796a7a70795a203cab11d8709afdc498bc7058c2769568aa655b1b1\ 39447f940335b3f7a847a304f3e200199465b93c509386c73884a3882659bbb4\ 9efdd34537884d08ec5c52705dbf745be4483b08d81814164087f41754c18b88\ c1a069057a21f938c02a3197872198b567a90b048e5b326d3c33ab388e2cd902\ 81a268a2b46f6e9c3e8c06945db0adab070153cb21a4d850ee5892cd714e7704\ 1a055b0a6307d0093a6c91b54b2ea3992928c5bb43cdbf74cf6160cfe8952015\ d8794f848a60620b0a555ad03a4045eb0aa263c6fd7c72296145a943a182fc43\ 6719917acb2c50e440b7f843b263741a646971fac1f1242f5e399b98474e571b\ 039763cdc39cc8a2f39940956dbec0b81ff3c8fe4276850c9dc58076f0f918ba\ 232289ba4b7eec7ab5994f07e356bfb724f86a599d9c6b11961b31e11b48b066\ bc054b615555bd8c7a45c61106749147401f8091bc2093ca5c499c33ccbbd93b\ 0517acc38901ac99fab5684c1451127b3e797f92005c6585a0c3a327d55b02ee\ c02396f4a749fa305b5c994ab0a4c24705cdf92ad8b1ade4f639c4f3ca05dc15\ 6860bd1e93a56f37a03dd9c1e057106913c41e57af4ac2c4f2d8631e6891749b\ 1517362ca094823320429e431a2e527bbfc63262c92027b97aa16a82c327058d\ 43774561b46edbb09f221b6872504dc6a4d0804d0012992842534975114de19a\ 61593c1ea7715d6232d2e1389e4a15674b3580177db061ca3ce8443ad76c111c\ 4964fb0c8436a22e31aeb853141213c4d0341e2ab128993712c1b5b13d7c1424\ 0a542acbc428136815c44657e63438613324f48ce09b6543b14154f8b9e6265d\ f5b777e2aac26e4a450feca2c730a79eb05177782c2b4b725e276f8d3b523646\ b8f1a06723c94529cbc9cce58bc56365ba044df9eacffb2393c06a0be6e281c8\ 7876477cca3476cfbd1caf4d590302933198f3ab6b279232984be7e1b73f6152\ b38a8b097cb9accb0df0a280f7502a31d630017aac73701b1a5284e889373373\ 582b9048fc2b054a4660524c3b5caba00a846d06d37d75596ed1768b9ae207ea\ 821cfffc17c8114c5fa13d6cd744493c0dea31811a9c85547b74dd04310b1996\ 4f503b6f105e780775a0747a831a2a0f581e082021fd1a8b049cae93562822cc\ b9e4489f2f0c8f2c2430930491877b7ca9358c2006172fd37700bb8208a8717d\ 926c9b35b992679971326b4c436278fb3764129a948343aca8ad3817c6a25cce\ c1f96e00d42eac7a6047b39825f3553712ab2aab647a26349090691e732cb137\ a45f64d0b8a4', / priv / -2: h'af95ba4ef8653e7bb31fe8363a081d6000e54565bb71c1a151d\ Reddy, et al. Expires 14 November 2026 [Page 61] Internet-Draft COSE HPKE PQ May 2026 d8c00309d005c59d68097d5800d4dc8d7bc45528d843a70b6211e09183e60aa2\ c992ff49b8695' } Figure 37: HPKE-12-KE COSE_Key (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 a50107025820da3c1ad21455112a22a022e2a9f3738002fc448ca06f10222076f8e2\ 4cb37c8803183f205904a01f3a20ac944450f00eb8456a6be0cffed5733a322f4373\ c10f0a333192be2e7421b7f9a3604a61ba09958c5ab622c19f17d7cad937af40342f\ 9d0287a04467485ccfe3b681c5706309902891d57fc3a948fe396b64b366127716ec\ ac90a59564aeb75002b60b891431964a330fb15a5e5504ebfc940981703858a70b45\ 5b7fbb43a99c06a2b759a02c215f0746cd4a94e473c794477355397e36d190768634\ 37b136ce260aabd0b413d412b2dc980812aa77fa96483c264c188946a8cd857793b7\ 87ba0c42363b12b6e4a2b1adf61dea4a47605a59602c2d7c6605ea3596363a525957\ 17b83c74c4b728f0c81593970def696fbd5960d9f0c138b7b1180c0796a7a70795a2\ 03cab11d8709afdc498bc7058c2769568aa655b1b139447f940335b3f7a847a304f3\ e200199465b93c509386c73884a3882659bbb49efdd34537884d08ec5c52705dbf74\ 5be4483b08d81814164087f41754c18b88c1a069057a21f938c02a3197872198b567\ a90b048e5b326d3c33ab388e2cd90281a268a2b46f6e9c3e8c06945db0adab070153\ cb21a4d850ee5892cd714e77041a055b0a6307d0093a6c91b54b2ea3992928c5bb43\ cdbf74cf6160cfe8952015d8794f848a60620b0a555ad03a4045eb0aa263c6fd7c72\ 296145a943a182fc436719917acb2c50e440b7f843b263741a646971fac1f1242f5e\ 399b98474e571b039763cdc39cc8a2f39940956dbec0b81ff3c8fe4276850c9dc580\ 76f0f918ba232289ba4b7eec7ab5994f07e356bfb724f86a599d9c6b11961b31e11b\ 48b066bc054b615555bd8c7a45c61106749147401f8091bc2093ca5c499c33ccbbd9\ 3b0517acc38901ac99fab5684c1451127b3e797f92005c6585a0c3a327d55b02eec0\ 2396f4a749fa305b5c994ab0a4c24705cdf92ad8b1ade4f639c4f3ca05dc156860bd\ 1e93a56f37a03dd9c1e057106913c41e57af4ac2c4f2d8631e6891749b1517362ca0\ 94823320429e431a2e527bbfc63262c92027b97aa16a82c327058d43774561b46edb\ b09f221b6872504dc6a4d0804d0012992842534975114de19a61593c1ea7715d6232\ d2e1389e4a15674b3580177db061ca3ce8443ad76c111c4964fb0c8436a22e31aeb8\ 53141213c4d0341e2ab128993712c1b5b13d7c14240a542acbc428136815c44657e6\ 3438613324f48ce09b6543b14154f8b9e6265df5b777e2aac26e4a450feca2c730a7\ 9eb05177782c2b4b725e276f8d3b523646b8f1a06723c94529cbc9cce58bc56365ba\ 044df9eacffb2393c06a0be6e281c87876477cca3476cfbd1caf4d590302933198f3\ ab6b279232984be7e1b73f6152b38a8b097cb9accb0df0a280f7502a31d630017aac\ 73701b1a5284e889373373582b9048fc2b054a4660524c3b5caba00a846d06d37d75\ 596ed1768b9ae207ea821cfffc17c8114c5fa13d6cd744493c0dea31811a9c85547b\ 74dd04310b19964f503b6f105e780775a0747a831a2a0f581e082021fd1a8b049cae\ 93562822ccb9e4489f2f0c8f2c2430930491877b7ca9358c2006172fd37700bb8208\ a8717d926c9b35b992679971326b4c436278fb3764129a948343aca8ad3817c6a25c\ cec1f96e00d42eac7a6047b39825f3553712ab2aab647a26349090691e732cb137a4\ 5f64d0b8a4215840af95ba4ef8653e7bb31fe8363a081d6000e54565bb71c1a151dd\ 8c00309d005c59d68097d5800d4dc8d7bc45528d843a70b6211e09183e60aa2c992f\ f49b8695 Reddy, et al. Expires 14 November 2026 [Page 62] Internet-Draft COSE HPKE PQ May 2026 Figure 38: HPKE-12-KE COSE_Key (Hex-Encoded CBOR) NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt / 96([ / protected / h'a10103', / unprotected / { / iv / 5: h'a121e56c3d426e69ce917fe3' }, / ciphertext / h'3a36b87e2d53080f2e52a2994b6c04babccbf27cfcaabed6e\ 10eff448ff2cb3b805efcb59e7101877f30d55760684e0ce472c9979170ad401\ ddb6fdd70fb879b2192e8720eea24de9d3d29f80e01a6438c0f4198c3409eccb\ 195816dc509c85dba59574e9d6286219af5bd78dfd13c25dd6de22b8a1a824dd\ 464edd4a51fd714ada330f404bef0debfa9e51ab6aba8cef919fd669102ea59c\ 907b5cecc962ca95f9b8a74b3ac2de437d1746f5478813d2f92e9f83be48ffd6\ cda04c63285cb3f422895bd41b1acee46a4b6640073af51ad3248b9c7e9304d9\ 332a68d819873d0f424185f3562a8d736054b361ae4c8c4e26f9f7242ff429fe\ 45921215e9e7b7387451c77790f8dd6677dce5f94c72ce86106403624af5bbf6\ 6dcd3d017ae838d02', / recipients / [ [ / protected / h'a201183f045820da3c1ad21455112a22a022e2a9f37380\ 02fc448ca06f10222076f8e24cb37c88', / unprotected / { / ek / -4: h'2c5249f8084eac277dd297f8a7c6cfb2ff13f86c680c1fa\ 5de6ee1e78cdf917bff9cabefa8445a3309d512c1f5046416b940c8aaecff1d1\ 29204900a0d100a28ef64b0983b421081e038e721c9b7dd52348b5be6ab678ca\ e398cd55fad307e4e7f4fb97728cdddb05e22a95db7f99ee17350141f659090c\ 2894499455df9f1d88a25cee3197f499683582994a09d026d271dc97e4b48d3b\ 78d3e8fcef38b9651d2e4ba038c0b8523dfa42dfeac1a5b8e4f4434b6a06a0e2\ ab10ded0e6940de3dbffb2a1633f2aed4440366640acfdaaab5cc149631b0139\ ab079a773b3d8e6cab0764426f06f77ca64c7dce75c58f4f8cde8d7cd72aae77\ d18f993ef865152d24d04d9352d482ad65f427d462e0ae9f4ea50e031a06875a\ afb5850ff7eca81c311e50858a2fde35ac327e765f7e0f1208b354762948a0fb\ f4c8f0ff0d97d3bd93a6b6c8c300e4696228fe2af60a9adafd00b1c7ec530cdb\ c56f0853a0400c7125b7d0bcb7db5083cf4531125880094e1ccb493ff2914b24\ eb29b396fcabb0c7a9f2156ea5a28fc8b9ee94c21a588dace4aa0bd7d2001f6a\ 05df667e7470c4b62882b3233f759d07a3194e4779778fa7117a347eb128bf7b\ 9df3c3def710a6f556b895f77939ff1e18c4b112262cbcf175c2a207cd5eb9d6\ eb38ed70746973f4d67e7477fa82969c3b5594dc43e0a8f29b2f8f2eda23827e\ b6283a2340f59022abc2f27d106497c4501859af3e7c50ca3fd8e136350547bd\ 29b5501004654e8d8438cc51ed32281cc2c4b9a9c8d8a2c81552926b1c3ef624\ 8c32eefead5c8303c6a38d5dece07855e1e2b3cea600e4edf9ce1db1e854eb39\ cf1067d004683189e55a964d0834129bfbd2b3bec2f1f58fc6e3d742bc09c26d\ bb59cb6ae746e0df59fd9e714c6ecdce7feb32cb199252dabdb34e60185e75d1\ 48b143d1a91f939af1c9339dd2c20b0bc0af87e694dc587233084968e77e90cb\ 869ba8578aeedd3d7420bd2ccd253f3ab48dd6009819e94ace223558cec54a16\ 35199a3a5b3fdc4aa3aa3ed965a06558a9224c3d1d410cbf689352c300ec60f8\ Reddy, et al. Expires 14 November 2026 [Page 63] Internet-Draft COSE HPKE PQ May 2026 47761248d1ca1009cbcac4a0d67e40c32ad7c8bc28a72ef2c53f9646d790ea72\ 2118404a033b8a5030804f633102be56506920143c65f2125c981bfbc939c14a\ 6338b8ce257d68368847472f9daa2a68db5e71d125780416796c406f6f07699f\ ca2a322631ef3646bd55097c6e7ba856ddbd2b60f7568c90d88ce0c2ff62f82a\ 17b4bfd2415559732e2d1df4e2b9b1de855ffcba9b29f9ff63d90fef6db94188\ 8b6988f22a9ebfa6180fc7f3e2666ae2edf7d345acb48339dc6491821e47e306\ db53f3785f87ae2dce1567a0b33e9e5ce5aa82854166d7670b396d6bd1e1e546\ 5032186d247a5c7a0e05f098951382fa3f821995943db26c1b4c56e503da58e9\ 3e94b7a60ca6ce2e35d61c80bf826aefff14e4ffe6e3f0f0bb5ce3effb72354d\ 088ca882d775d3ce4e8435210dd6859118b76932e63c14de0e5ed149c626afa4\ 5f58cbffe01a3b1f3' }, / ciphertext / h'588672ac7f578fbee9a786df21a1afa2f8d45647485c6\ ad74b04887016a74fee077784d67433fae3642f285348f5bb11' ] ] ]) Figure 39: HPKE-12-KE COSE_Encrypt (Diagnostic Notation) Reddy, et al. Expires 14 November 2026 [Page 64] Internet-Draft COSE HPKE PQ May 2026 NOTE: '\' line wrapping per RFC 8792 d8608443a10103a1054ca121e56c3d426e69ce917fe35901213a36b87e2d53080f2e\ 52a2994b6c04babccbf27cfcaabed6e10eff448ff2cb3b805efcb59e7101877f30d5\ 5760684e0ce472c9979170ad401ddb6fdd70fb879b2192e8720eea24de9d3d29f80e\ 01a6438c0f4198c3409eccb195816dc509c85dba59574e9d6286219af5bd78dfd13c\ 25dd6de22b8a1a824dd464edd4a51fd714ada330f404bef0debfa9e51ab6aba8cef9\ 19fd669102ea59c907b5cecc962ca95f9b8a74b3ac2de437d1746f5478813d2f92e9\ f83be48ffd6cda04c63285cb3f422895bd41b1acee46a4b6640073af51ad3248b9c7\ e9304d9332a68d819873d0f424185f3562a8d736054b361ae4c8c4e26f9f7242ff42\ 9fe45921215e9e7b7387451c77790f8dd6677dce5f94c72ce86106403624af5bbf66\ dcd3d017ae838d0281835827a201183f045820da3c1ad21455112a22a022e2a9f373\ 8002fc448ca06f10222076f8e24cb37c88a1235904402c5249f8084eac277dd297f8\ a7c6cfb2ff13f86c680c1fa5de6ee1e78cdf917bff9cabefa8445a3309d512c1f504\ 6416b940c8aaecff1d129204900a0d100a28ef64b0983b421081e038e721c9b7dd52\ 348b5be6ab678cae398cd55fad307e4e7f4fb97728cdddb05e22a95db7f99ee17350\ 141f659090c2894499455df9f1d88a25cee3197f499683582994a09d026d271dc97e\ 4b48d3b78d3e8fcef38b9651d2e4ba038c0b8523dfa42dfeac1a5b8e4f4434b6a06a\ 0e2ab10ded0e6940de3dbffb2a1633f2aed4440366640acfdaaab5cc149631b0139a\ b079a773b3d8e6cab0764426f06f77ca64c7dce75c58f4f8cde8d7cd72aae77d18f9\ 93ef865152d24d04d9352d482ad65f427d462e0ae9f4ea50e031a06875aafb5850ff\ 7eca81c311e50858a2fde35ac327e765f7e0f1208b354762948a0fbf4c8f0ff0d97d\ 3bd93a6b6c8c300e4696228fe2af60a9adafd00b1c7ec530cdbc56f0853a0400c712\ 5b7d0bcb7db5083cf4531125880094e1ccb493ff2914b24eb29b396fcabb0c7a9f21\ 56ea5a28fc8b9ee94c21a588dace4aa0bd7d2001f6a05df667e7470c4b62882b3233\ f759d07a3194e4779778fa7117a347eb128bf7b9df3c3def710a6f556b895f77939f\ f1e18c4b112262cbcf175c2a207cd5eb9d6eb38ed70746973f4d67e7477fa82969c3\ b5594dc43e0a8f29b2f8f2eda23827eb6283a2340f59022abc2f27d106497c450185\ 9af3e7c50ca3fd8e136350547bd29b5501004654e8d8438cc51ed32281cc2c4b9a9c\ 8d8a2c81552926b1c3ef6248c32eefead5c8303c6a38d5dece07855e1e2b3cea600e\ 4edf9ce1db1e854eb39cf1067d004683189e55a964d0834129bfbd2b3bec2f1f58fc\ 6e3d742bc09c26dbb59cb6ae746e0df59fd9e714c6ecdce7feb32cb199252dabdb34\ e60185e75d148b143d1a91f939af1c9339dd2c20b0bc0af87e694dc587233084968e\ 77e90cb869ba8578aeedd3d7420bd2ccd253f3ab48dd6009819e94ace223558cec54\ a1635199a3a5b3fdc4aa3aa3ed965a06558a9224c3d1d410cbf689352c300ec60f84\ 7761248d1ca1009cbcac4a0d67e40c32ad7c8bc28a72ef2c53f9646d790ea7221184\ 04a033b8a5030804f633102be56506920143c65f2125c981bfbc939c14a6338b8ce2\ 57d68368847472f9daa2a68db5e71d125780416796c406f6f07699fca2a322631ef3\ 646bd55097c6e7ba856ddbd2b60f7568c90d88ce0c2ff62f82a17b4bfd2415559732\ e2d1df4e2b9b1de855ffcba9b29f9ff63d90fef6db941888b6988f22a9ebfa6180fc\ 7f3e2666ae2edf7d345acb48339dc6491821e47e306db53f3785f87ae2dce1567a0b\ 33e9e5ce5aa82854166d7670b396d6bd1e1e5465032186d247a5c7a0e05f09895138\ 2fa3f821995943db26c1b4c56e503da58e93e94b7a60ca6ce2e35d61c80bf826aeff\ f14e4ffe6e3f0f0bb5ce3effb72354d088ca882d775d3ce4e8435210dd6859118b76\ 932e63c14de0e5ed149c626afa45f58cbffe01a3b1f35830588672ac7f578fbee9a7\ 86df21a1afa2f8d45647485c6ad74b04887016a74fee077784d67433fae3642f2853\ 48f5bb11 Reddy, et al. Expires 14 November 2026 [Page 65] Internet-Draft COSE HPKE PQ May 2026 Figure 40: HPKE-12-KE COSE_Encrypt (Hex-Encoded CBOR) A.11. HPKE-13 NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'423cd82d6d196a643d0f928c0f026e178391d6602b0b4aa0458de\ 094758b4562', / alg / 3: 64 / HPKE-13 /, / pub / -1: h'e7da03e1e9a9593b4c84e47ba465720442846f996db605212130\ aaf397b2246a726576b9eb077e1dfa078fd331338a60e127bf8b09a3044659bf\ 95076d8a68506296f90161e421a3082bafb63200a1f01284d11a0694367411a7\ 917781199871fc43c0dc5c6fdf7b58f5602850d5611046b5b11b80c0b2397457\ bc6512c30c2528cfd875031a5ada9c4fd4f9668fa811b436b27c053d9af59986\ 1a70677c9d6e72048cf14b830c0f60650262d363f3b8b82b86876b641c5a5c89\ 95238ed2e9821c525bb04b0d2f454d690b2279258fff6141f7499806e42c6395\ 0237583ca7e0c589c580004b54134bae9187bd5f9bb7cfacbb03a05bf47c8016\ 1287e137a56ab4bbc527c12bac712ba3296c6ccfe58481a1917c30105e30d6cb\ c0d489f5d94c2986663c83bb67f6386e39675330ac2be682fec1116c495a4b31\ 622c8988c10a7520cc6e0be8a0cea963b717a96170a29d18bcca1ca21cd32e02\ 50c901c2cbd75b96edf6976f627739dac52eb74a8f0358ace74cc3cb9969ec57\ 916742525295f02749ac128ac776baa09029521337940a25caab93797786c750\ 2bcb2846b9a94110fac523744e72044758815a098145ed866391507b09828e54\ ea5758e7671c248d38f3165ad1af54445745b7b42ba79e5f489707f63175d072\ ab72300887335f0600d65b998ca8cc5ce463bffa954f323b1cf04579519d5c87\ 394f14c0449475e65104a0b44838fbb371e936abe2a5cb22334aa66aac779ead\ e46124704f96232c25818e02c47f3522cbc700c75a080ee66ab19f1a0dc95317\ 60f8317ab07beb779966dc2306ea1bbc6a70b4dc208e5aa664b7cb3f5c2a75ca\ 4836585e419710b2320edd8756210bb4d55b2f9a03c0964480627aa486625b9c\ 393745ca8674767315e92471ab36fec4ab06c11daa1b105c15a86243aaadb2cf\ e4ca9a21a2a342e3b0bad0a0b143a82c8986c1cc293585be809ca3e1d7240df8\ 6ba9c376ceb7905be82a98c8275d465ae62131f3ec5ae6c45099598a13096cdf\ f1a932bb54576c86d9e94f16d4c0947c59b205239be131c60c669b26a0b2dcc9\ 1450ab98902a3422a753d11eda968acd0070eea8a132f341342439bed990abe0\ 56c0340378cc116a2258255a869cd3ce50aa13db7853537acfa2c00672da4e0d\ 53b214f2c763b668425a8a93067b17f75b4962c944ec8556b6a170f32db7801f\ ca2a334aa949020a5f4be981c627a8e161c3ffb1b11de4b35bd5a4fa99a69438\ b2b6a6b0f65c820c36672f1513daa179e5242ebcf62bf89160c9599ae0bb01da\ 4011212750d36790c19bc19584c72b810df5f84532f4b631961f6ce289a1c68a\ 39aa7e763702316a7cca8c943fd38ab9a69bb3da39d5ba8a0a072846a163a964\ 190965c181b0cec81021030949472722a23787e8db54043c52334b7f235abc95\ 0962f6734628792518477ceaca66d6744c4c0473cbeaa61939546fc83d1d4bc5\ de5cb9d7a62829e54172e529a54a74bf8bb64e67bf96584d6b9105fba207c9b8\ cffd550183834e1a6184e7d90a5d4471880533f2f89d4962cef51906d4842836\ d27daf7532c7ec28153529dc80bf78709f03819be45948a8351c09164890780e\ a1d0287dbb56c9045990016cffc8904b55064fe3b6e5a8c00f68cc9c08176d63\ Reddy, et al. Expires 14 November 2026 [Page 66] Internet-Draft COSE HPKE PQ May 2026 aa76b22f45a3243a797440e399c0a90c7e8939def3aa449ba63bc74622e08ae4\ 8500451749b2917c76432cae4cb6339040fd0a9f18867bbd87c6fcb7227cda50\ 0310a3ef7aab359642120587dca56ad1069a477408317192f8083b2cc602de53\ 4f07c54e52f802eb011921d99cb78351e3c20f3438ce122846f2acc582d919f2\ b749e75500de5145319851b2e723f861a484284646489be2bc4bf919288b955b\ 770c5990e6083038535d8377a54386fb6a74678cb8fd37b34f706f6ed9b31033\ a24948923af3154a986c11e024bf8c28cbc85ef390cfc71330b000a0a5e94a5f\ e863a9831aa2db7ef160a1b6bac43733c797177a1fb8a9a32a3d9c00a4f0c91e\ e7540207133563674bf9f2c42a33036e54b9f70b24d721c8fc117abba91d0c08\ 6f7f2350ff883eb85c6a4a481b0b5158b3b8cd82e72224450549f36d6b864351\ cc96aeb9879b29a6eddc06cc7056a1a05cfdc23b821346336c86856bb75d274b\ a7568b9da0a24577986f950d8915d42fa08d02aa742ba1951e4c68c14b040485\ 7da80f8188b8', / priv / -2: h'24a7ee9c4a51fcef865fc3de9c07231e5dfb141de448fdd7eaf\ f0183c1c8708475b27ca68d08e25a899c02ad7b1db63279e3a6db22048338ee9\ dc5c31257d76c' } Figure 41: HPKE-13 COSE_Key (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 a50107025820423cd82d6d196a643d0f928c0f026e178391d6602b0b4aa0458de094\ 758b456203184020590620e7da03e1e9a9593b4c84e47ba465720442846f996db605\ 212130aaf397b2246a726576b9eb077e1dfa078fd331338a60e127bf8b09a3044659\ bf95076d8a68506296f90161e421a3082bafb63200a1f01284d11a0694367411a791\ 7781199871fc43c0dc5c6fdf7b58f5602850d5611046b5b11b80c0b2397457bc6512\ c30c2528cfd875031a5ada9c4fd4f9668fa811b436b27c053d9af599861a70677c9d\ 6e72048cf14b830c0f60650262d363f3b8b82b86876b641c5a5c8995238ed2e9821c\ 525bb04b0d2f454d690b2279258fff6141f7499806e42c63950237583ca7e0c589c5\ 80004b54134bae9187bd5f9bb7cfacbb03a05bf47c80161287e137a56ab4bbc527c1\ 2bac712ba3296c6ccfe58481a1917c30105e30d6cbc0d489f5d94c2986663c83bb67\ f6386e39675330ac2be682fec1116c495a4b31622c8988c10a7520cc6e0be8a0cea9\ 63b717a96170a29d18bcca1ca21cd32e0250c901c2cbd75b96edf6976f627739dac5\ 2eb74a8f0358ace74cc3cb9969ec57916742525295f02749ac128ac776baa0902952\ 1337940a25caab93797786c7502bcb2846b9a94110fac523744e72044758815a0981\ 45ed866391507b09828e54ea5758e7671c248d38f3165ad1af54445745b7b42ba79e\ 5f489707f63175d072ab72300887335f0600d65b998ca8cc5ce463bffa954f323b1c\ f04579519d5c87394f14c0449475e65104a0b44838fbb371e936abe2a5cb22334aa6\ 6aac779eade46124704f96232c25818e02c47f3522cbc700c75a080ee66ab19f1a0d\ c9531760f8317ab07beb779966dc2306ea1bbc6a70b4dc208e5aa664b7cb3f5c2a75\ ca4836585e419710b2320edd8756210bb4d55b2f9a03c0964480627aa486625b9c39\ 3745ca8674767315e92471ab36fec4ab06c11daa1b105c15a86243aaadb2cfe4ca9a\ 21a2a342e3b0bad0a0b143a82c8986c1cc293585be809ca3e1d7240df86ba9c376ce\ b7905be82a98c8275d465ae62131f3ec5ae6c45099598a13096cdff1a932bb54576c\ 86d9e94f16d4c0947c59b205239be131c60c669b26a0b2dcc91450ab98902a3422a7\ 53d11eda968acd0070eea8a132f341342439bed990abe056c0340378cc116a225825\ 5a869cd3ce50aa13db7853537acfa2c00672da4e0d53b214f2c763b668425a8a9306\ Reddy, et al. Expires 14 November 2026 [Page 67] Internet-Draft COSE HPKE PQ May 2026 7b17f75b4962c944ec8556b6a170f32db7801fca2a334aa949020a5f4be981c627a8\ e161c3ffb1b11de4b35bd5a4fa99a69438b2b6a6b0f65c820c36672f1513daa179e5\ 242ebcf62bf89160c9599ae0bb01da4011212750d36790c19bc19584c72b810df5f8\ 4532f4b631961f6ce289a1c68a39aa7e763702316a7cca8c943fd38ab9a69bb3da39\ d5ba8a0a072846a163a964190965c181b0cec81021030949472722a23787e8db5404\ 3c52334b7f235abc950962f6734628792518477ceaca66d6744c4c0473cbeaa61939\ 546fc83d1d4bc5de5cb9d7a62829e54172e529a54a74bf8bb64e67bf96584d6b9105\ fba207c9b8cffd550183834e1a6184e7d90a5d4471880533f2f89d4962cef51906d4\ 842836d27daf7532c7ec28153529dc80bf78709f03819be45948a8351c0916489078\ 0ea1d0287dbb56c9045990016cffc8904b55064fe3b6e5a8c00f68cc9c08176d63aa\ 76b22f45a3243a797440e399c0a90c7e8939def3aa449ba63bc74622e08ae4850045\ 1749b2917c76432cae4cb6339040fd0a9f18867bbd87c6fcb7227cda500310a3ef7a\ ab359642120587dca56ad1069a477408317192f8083b2cc602de534f07c54e52f802\ eb011921d99cb78351e3c20f3438ce122846f2acc582d919f2b749e75500de514531\ 9851b2e723f861a484284646489be2bc4bf919288b955b770c5990e6083038535d83\ 77a54386fb6a74678cb8fd37b34f706f6ed9b31033a24948923af3154a986c11e024\ bf8c28cbc85ef390cfc71330b000a0a5e94a5fe863a9831aa2db7ef160a1b6bac437\ 33c797177a1fb8a9a32a3d9c00a4f0c91ee7540207133563674bf9f2c42a33036e54\ b9f70b24d721c8fc117abba91d0c086f7f2350ff883eb85c6a4a481b0b5158b3b8cd\ 82e72224450549f36d6b864351cc96aeb9879b29a6eddc06cc7056a1a05cfdc23b82\ 1346336c86856bb75d274ba7568b9da0a24577986f950d8915d42fa08d02aa742ba1\ 951e4c68c14b0404857da80f8188b821584024a7ee9c4a51fcef865fc3de9c07231e\ 5dfb141de448fdd7eaff0183c1c8708475b27ca68d08e25a899c02ad7b1db63279e3\ a6db22048338ee9dc5c31257d76c Figure 42: HPKE-13 COSE_Key (Hex-Encoded CBOR) NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt0 / 16([ / protected / h'a1011840', / unprotected / { / kid / 4: h'423cd82d6d196a643d0f928c0f026e178391d6602b0b4aa0458\ de094758b4562', / ek / -4: h'199f52b68d2a9093bf80f906e6bbaa63af8a7a1a9dab6d5a288\ 018dbeb45c7bf8e1d51a74e9a0549dfd5f2b1b325004a50c7584c1e88af9bbae\ 4559b833ae1711912798ea6093542c2afbdddb9feb1deda0931e29529466fc36\ 6772574867b512a175d4181ae2ffd66c8d57f6d61f253fd451a5ea04971f64ae\ 6519965a9c43d2627e7eb4926ebdcaf9fcc36a9cc184d80668aa417a20c44981\ aa1b6aeb106114c4f8a842a5c67ceb404c27d4316b0a561955ddf7856334ab34\ c5fff65366f914c22f9b375fef57b1627b29e0d84e097f4de5175eecd5a369fb\ a10a974960ab99242041a566b310553eb71aa5a3963d9d5060c09c01d26cca65\ 4b91bc36ad9460672ff173da460f5947982993bc88b1d825ab16e262c8344e2f\ 84de94b94644b80d1c2ee64565887181d036ec6fa6f20543e250e1b4648f375b\ f39bda55a2799993703106558f1d811bb9b6d699116e858107d2076bef5e16d4\ 7dfb430d9b12a1adfa3e57a1091bf79103f0d61fab364195902f759d1819c695\ f42c95d4405cc1f11813c051c825e9865a5a8f679e5a291079b55c51b3917be8\ 0522c987cf40dca483378587bf07a7575c1e6f7cc5edae846cd08d5f87df7630\ Reddy, et al. Expires 14 November 2026 [Page 68] Internet-Draft COSE HPKE PQ May 2026 52002175b391b06a13c23a6a18626f91696ad35be92a4cd7c55c40b369c38b3c\ 0225d15cf4e12a08ecc6dc5e9871d715b181e6b2bcbf94b6c207ae99b9b59be5\ e7bd2a16a1460cd3d1aeb90f54511337283acaa30b9751d840e2db5436717df6\ fdcb4d02432f3a6179d66def397266c5f5202e8e4e6b8a99c6201a2ba052ba1d\ 5c0b80732f9e664fe9a081e9318d86b67c205bfd712c230f25e6c169f0848f84\ d8157f674c2dc695d9d8360f7630fbf279d3b91d973ac991dd7308abfe13c6ef\ 19e813db506483c4bb8dd9801f451986d8ba4982e366730bfef6d6c3b375fb85\ a9fdda55955379158654ac7a495a47f81ab481960cbeb4886b7515381204f5c3\ 04816800ff9d9dc54c2aba95c6a9311dfa6e1e4d335bc90fc5ec233c677ef6b7\ d3c9b17fa236b7de673216866f8ceaa2d4692d62798826ab8bae7996cc23bccb\ e0eedbbda41a67ba63665c13e210f2a2516e5f2b904f35f6a3a49fb895b22cbe\ 48618a03f7d608d8c3afd824d08d037dc1ecc7d4c6b266d69aae37c73ea83e99\ 7a6caecc5f03d1d0217df4defd65d90f8e7669e993547954b57cb58203c8b048\ 30257b5622b7fa619aaec33a0efed5dae20439a782c097f530a55c690bb5c156\ 5b6df88ba667d74e31dc43e7648dc555d2f66c03d8ad1e20c202686308593cfb\ b8d067f5c94f57b7871f0e5822a6c3e8ff7e0011baf8e6c80a534e81a2b4681e\ 7fb7ca7370bf0458d40f6520b03aea435e478078c18a067040fddd14771a9ccd\ ac526a14fe8f947c734441eede0d045607e812f9fd4990d89a01ada99f07b6d4\ b05ab1e9fabd3b13d25e7fe01f96579895f296367120c7d812a56afdaeb176d4\ 52079f31bc1561193448e07aec4647fa1230708e7fb216547582af0c890aaffa\ 087e507ccb4ceac15aef09bf82cd448aa62d48e337339cabac9e0c535f03fd93\ 416a22cb33054ba3a1cb1636dd0965c9a2ff56667f8b0d51e965d5b2bb04f0aa\ 15f194db99dcacf5c26a2ba92267fa145fc2e24625072e3346dbe989d21acf3b\ 7b113f36f987dd81ca01637cd540a817129560331cd383eb9ad3761f34a5468a\ b8d13ba6abeb0d19b25c3d0a2a7e583170f9a559b7952cc7f4379dcdd6e0f383\ 3106c81ad2d8f2a024054033b267e8d6a4c89d552ac7af35f62ec47f6550d796\ 7faad29d7ab089bf29ac01e13a7ceecf61f68998c1608e8c74eadcd4063cbf30\ d3d580062b86242af27fc087152bd329c0d3918690b993e0e9bb78a2fbed4984\ 430abb25fae063646ee3da9ecd936fca7984c0a690d0477cbe393f170ecb3159\ 50d98dee64b66a83634472c757ae37dd51ad7eea26937d4d18a20d5c2f10e3ff\ ece64fe26b6c2d0ae71780c7b8ec4d4d3fe0045d5c8b26035faa039210694f88\ cb8f2792c54ac1a91bf0ed7cfd04c3ed4df849a37120e3752f62cf18dd5b3965\ aa215e561ae8b24e3480b1ee52a7960d302cab769123db55dc4dc2e03c10ac0c\ f41fec8104cc1104907f93cc9c35ee571390e1132f7978e2b1f6f76fcaee62e2\ 627d6ddd79e29fd21577fd281c64318aedea8a2eb7bfecd23b0e2507c31ad1de\ c30bc16b2312b' }, / ciphertext / h'e29b847767387a40e1e4c6f1d87a4c15d3946751f85e71643\ 3078c6456d5c98c54b494a5b7b9e6fb072be4a99af3e01c8a306583e274fd1d5\ 5f2ffe0d36529c7e016950450dc2002f08106f1d33debc1068b816e58b158c8a\ fdee84a0d4c0a9d4fdad7e0ed655a2b7c8adbe9308eed4bf36409c86555c716c\ c36d3e4a167f1691d21357d80de14fcbd095be2c425d84c81adacbab738daa67\ 7f87e670881f82f85a3dd7588ca34fa932c5d5f30f6cb1e532e25b3b13ed09ab\ 01810c8b5050a7362de24a5345b9f348e767884ead86428f65e23a0c59b2cc9d\ 64ec21541e0a5f429fb96731b7f308daf53aef5ba37e19a232a7abf25f008f0c\ ea0bf2525f1cb7c91a8ca4d19be3c2e3851d8b75397ff9cae9af640af920e657\ 7172cbfa6cff90843' ]) Reddy, et al. Expires 14 November 2026 [Page 69] Internet-Draft COSE HPKE PQ May 2026 Figure 43: HPKE-13 COSE_Encrypt0 (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 d08344a1011840a2045820423cd82d6d196a643d0f928c0f026e178391d6602b0b4a\ a0458de094758b456223590620199f52b68d2a9093bf80f906e6bbaa63af8a7a1a9d\ ab6d5a288018dbeb45c7bf8e1d51a74e9a0549dfd5f2b1b325004a50c7584c1e88af\ 9bbae4559b833ae1711912798ea6093542c2afbdddb9feb1deda0931e29529466fc3\ 66772574867b512a175d4181ae2ffd66c8d57f6d61f253fd451a5ea04971f64ae651\ 9965a9c43d2627e7eb4926ebdcaf9fcc36a9cc184d80668aa417a20c44981aa1b6ae\ b106114c4f8a842a5c67ceb404c27d4316b0a561955ddf7856334ab34c5fff65366f\ 914c22f9b375fef57b1627b29e0d84e097f4de5175eecd5a369fba10a974960ab992\ 42041a566b310553eb71aa5a3963d9d5060c09c01d26cca654b91bc36ad9460672ff\ 173da460f5947982993bc88b1d825ab16e262c8344e2f84de94b94644b80d1c2ee64\ 565887181d036ec6fa6f20543e250e1b4648f375bf39bda55a2799993703106558f1\ d811bb9b6d699116e858107d2076bef5e16d47dfb430d9b12a1adfa3e57a1091bf79\ 103f0d61fab364195902f759d1819c695f42c95d4405cc1f11813c051c825e9865a5\ a8f679e5a291079b55c51b3917be80522c987cf40dca483378587bf07a7575c1e6f7\ cc5edae846cd08d5f87df763052002175b391b06a13c23a6a18626f91696ad35be92\ a4cd7c55c40b369c38b3c0225d15cf4e12a08ecc6dc5e9871d715b181e6b2bcbf94b\ 6c207ae99b9b59be5e7bd2a16a1460cd3d1aeb90f54511337283acaa30b9751d840e\ 2db5436717df6fdcb4d02432f3a6179d66def397266c5f5202e8e4e6b8a99c6201a2\ ba052ba1d5c0b80732f9e664fe9a081e9318d86b67c205bfd712c230f25e6c169f08\ 48f84d8157f674c2dc695d9d8360f7630fbf279d3b91d973ac991dd7308abfe13c6e\ f19e813db506483c4bb8dd9801f451986d8ba4982e366730bfef6d6c3b375fb85a9f\ dda55955379158654ac7a495a47f81ab481960cbeb4886b7515381204f5c30481680\ 0ff9d9dc54c2aba95c6a9311dfa6e1e4d335bc90fc5ec233c677ef6b7d3c9b17fa23\ 6b7de673216866f8ceaa2d4692d62798826ab8bae7996cc23bccbe0eedbbda41a67b\ a63665c13e210f2a2516e5f2b904f35f6a3a49fb895b22cbe48618a03f7d608d8c3a\ fd824d08d037dc1ecc7d4c6b266d69aae37c73ea83e997a6caecc5f03d1d0217df4d\ efd65d90f8e7669e993547954b57cb58203c8b04830257b5622b7fa619aaec33a0ef\ ed5dae20439a782c097f530a55c690bb5c1565b6df88ba667d74e31dc43e7648dc55\ 5d2f66c03d8ad1e20c202686308593cfbb8d067f5c94f57b7871f0e5822a6c3e8ff7\ e0011baf8e6c80a534e81a2b4681e7fb7ca7370bf0458d40f6520b03aea435e47807\ 8c18a067040fddd14771a9ccdac526a14fe8f947c734441eede0d045607e812f9fd4\ 990d89a01ada99f07b6d4b05ab1e9fabd3b13d25e7fe01f96579895f296367120c7d\ 812a56afdaeb176d452079f31bc1561193448e07aec4647fa1230708e7fb21654758\ 2af0c890aaffa087e507ccb4ceac15aef09bf82cd448aa62d48e337339cabac9e0c5\ 35f03fd93416a22cb33054ba3a1cb1636dd0965c9a2ff56667f8b0d51e965d5b2bb0\ 4f0aa15f194db99dcacf5c26a2ba92267fa145fc2e24625072e3346dbe989d21acf3\ b7b113f36f987dd81ca01637cd540a817129560331cd383eb9ad3761f34a5468ab8d\ 13ba6abeb0d19b25c3d0a2a7e583170f9a559b7952cc7f4379dcdd6e0f3833106c81\ ad2d8f2a024054033b267e8d6a4c89d552ac7af35f62ec47f6550d7967faad29d7ab\ 089bf29ac01e13a7ceecf61f68998c1608e8c74eadcd4063cbf30d3d580062b86242\ af27fc087152bd329c0d3918690b993e0e9bb78a2fbed4984430abb25fae063646ee\ 3da9ecd936fca7984c0a690d0477cbe393f170ecb315950d98dee64b66a83634472c\ 757ae37dd51ad7eea26937d4d18a20d5c2f10e3ffece64fe26b6c2d0ae71780c7b8e\ c4d4d3fe0045d5c8b26035faa039210694f88cb8f2792c54ac1a91bf0ed7cfd04c3e\ Reddy, et al. Expires 14 November 2026 [Page 70] Internet-Draft COSE HPKE PQ May 2026 d4df849a37120e3752f62cf18dd5b3965aa215e561ae8b24e3480b1ee52a7960d302\ cab769123db55dc4dc2e03c10ac0cf41fec8104cc1104907f93cc9c35ee571390e11\ 32f7978e2b1f6f76fcaee62e2627d6ddd79e29fd21577fd281c64318aedea8a2eb7b\ fecd23b0e2507c31ad1dec30bc16b2312b590121e29b847767387a40e1e4c6f1d87a\ 4c15d3946751f85e716433078c6456d5c98c54b494a5b7b9e6fb072be4a99af3e01c\ 8a306583e274fd1d55f2ffe0d36529c7e016950450dc2002f08106f1d33debc1068b\ 816e58b158c8afdee84a0d4c0a9d4fdad7e0ed655a2b7c8adbe9308eed4bf36409c8\ 6555c716cc36d3e4a167f1691d21357d80de14fcbd095be2c425d84c81adacbab738\ daa677f87e670881f82f85a3dd7588ca34fa932c5d5f30f6cb1e532e25b3b13ed09a\ b01810c8b5050a7362de24a5345b9f348e767884ead86428f65e23a0c59b2cc9d64e\ c21541e0a5f429fb96731b7f308daf53aef5ba37e19a232a7abf25f008f0cea0bf25\ 25f1cb7c91a8ca4d19be3c2e3851d8b75397ff9cae9af640af920e6577172cbfa6cf\ f90843 Figure 44: HPKE-13 COSE_Encrypt0 (Hex-Encoded CBOR) A.12. HPKE-13-KE NOTE: '\' line wrapping per RFC 8792 { / kty / 1: 7, / kid / 2: h'1b28d7cad6a4ba7cdfceac81643186b3b4853d872f0d35e427b8f\ e98260ef2a6', / alg / 3: 65 / HPKE-13-KE /, / pub / -1: h'877b92a75b89cff82420abca15213ebfa20ced24378516690e9c\ 6bfb75b29bc943bf344ceb252b38eccf40a16d51c53c170c6152656532778d8b\ b31e9f2016fc0c99b646820216998564541a75167023599053bc2bbc8d539a97\ d0acc3139225c9b8941f91a95d6acbc797cda8553b069cc27b72ba5f924774b1\ be49c7ce55f82ce046a86b29b85bca062f1a52ac1a99ff0621b1288609d82e4c\ 859fbb8a2d98533268a218e3abb345347676fac41f57990e151cfe5b142d4486\ 4be22ec04c8123954d1e0263d1846ec44814f765ad14b95a46281c92cccd47aa\ ab9f7420419742fcf93be2a58f265a5b30886cfb2b474ea6618bb465b8851e0c\ c96339234c34cc3b9e17ba95ca3ad6c4838ab2b87de605a82723322a0bdf28a9\ 3c99165a5577d4c33d8b3697192521ae835d024c0c08369480f58dffc75eed9a\ 4d4c872773793921c520d6a7b43f69986f0c0990f0cae62295b1ca9d261300e7\ 050ae9b3ba55bb250c92217c8a776b8b5eb3514588342dad306dcfbbc900c33c\ 24a044cbc9c848c7ca33d651bb717ffd4bc3166b24bdd97e60c759e52c42b780\ 781e765b77ab7f3335865d9a05a8eb9a3c420bce171e9cd1a453195d2307c833\ d50a55e1ae60136b38dc9e7ff06e0a98c62c253447056b0091312e3a203bfba4\ 2b68a91ccb80fde001fd834469081aaca41bf99a688eb519b7c5cc4853367404\ c84c61ce22b9240501662301d07c247dd9fc26cf56334465211d745f8d0185db\ 7839bbf20423fc0f0a898f01013787e85a8c003d6d5c62918726810c946ff117\ 5f345d25e5580b58c559a32247a4705fa4ac3fe7c188823193b7548406345d79\ 49819a24d8f5312ee22aae85745f8036559319426a1a140bb7e428a049ea3791\ 7296d54914e8a18a610380d390a7b1527b2662768622615df14fe198bbef1490\ 17b4a8c50b22e4fab3ba0940da483631192ad1f0b61f1196a1539eef25814c40\ 2f96f107bdb828de5ba9f0c502b29a448da42025b2453a295ba6257b6ca247fd\ Reddy, et al. Expires 14 November 2026 [Page 71] Internet-Draft COSE HPKE PQ May 2026 20a40df13d2ea5142de3b291757cb69691b5e7b04dd650cc98952d590ba6f425\ 54942a1a829b0bc7170fd5243c02410fb01212fbc1612aa548c232707ba72597\ 64cddb86bc93be3bd895966b608ac4b9c29c7cdab7ba233813d5bb2788110263\ 897e005b37eedb83849650a7c90eba547889c09c7a6c84ccc72220b234322101\ ff8b2469798563f9ba89fcb53cbb3f1024595db5a661164ee93a6206550380b4\ a2c2055255421bc80c4becb3a255943cff9abfc48788b3252a62471e70649d52\ c79cecc2489d84253c9293ed6b25300017df397da38b9bb776815d37bca52579\ bb374d54548bf2b29e775956c390644f9aa2252632d04bc37a663b314791829c\ 27b720c51d1483f7e12cd4e7c1f38b6ad98a5e1c14768351a76da1267e529bfb\ 7bb6d1e07d49086b1e893b93097f3920849ba10b8dfb08d6b9b15dbc65fda93e\ 004319fe1bbbe4ccab73e00335f6167b1991259156b426355491c11a32956fc7\ 98f6ea73c363c8d5b371d4200891342d60e09b8b79cadc415281d56e75930045\ b2203d1717d420ae9c58047d38119bf97111caba42471ae7d25c7d64c017848e\ 741a22f23427fb2a135fcb99acbaaa1f68021d4b9367c0389c150b81207c67bb\ 1b74d07f94e7729ffcab169002004025eda27a31685bfad3c227c05287b430d7\ 2a425b355785549c45e83db6d90bd2c306632c912390767607a960985530bc2c\ 4002207697c21921224d64acd93a4ba558b4ce7c30f503c849021ada958df07b\ 793d25be8b279f55d3180e8b03cdb3a842b60dc1576107f93a32189f2a928eaf\ 302841960a77083492b295edfb64abba50fbd31ce47a308cc9837cb865b44009\ 1ed56d6f3cb79e7608d3e2788006b9887b36e940bd2101002c59361b1c7cf243\ b708fbb74afc462bccc3fa396b82f31f7d5344c60a629aa821373c9084f312c3\ 601e03c539fdfa45f5c6cdd14409c7bb7a82613573b9247a93404d179c11e7ac\ 76bbca925cb1b916b323818beea94a1d4ca492d4c1c1041f84da3f54c540ac64\ 94fe08ccf9569620427179f3099d016c82a43400bbc102cc741c22b539c52422\ e59a69f71c2b6c8abfa56f7fdc32b6e9718979270e484c57b81359829cb87583\ 60026a7b3a8195657acaf1865a41aa5aabaaec7c323d8fae01355bbbc99d2b3f\ c7dac82661d4', / priv / -2: h'4cae5ae552c32ce31cc6c60d4b8f6f1a36b034c325d016e6f38\ e8f3d5c0f00a32f6b0990170c15043f8eb6137e2eb1965ba7fe7768f3fd19487\ 2748f85c920e4' } Figure 45: HPKE-13-KE COSE_Key (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 a501070258201b28d7cad6a4ba7cdfceac81643186b3b4853d872f0d35e427b8fe98\ 260ef2a603184120590620877b92a75b89cff82420abca15213ebfa20ced24378516\ 690e9c6bfb75b29bc943bf344ceb252b38eccf40a16d51c53c170c6152656532778d\ 8bb31e9f2016fc0c99b646820216998564541a75167023599053bc2bbc8d539a97d0\ acc3139225c9b8941f91a95d6acbc797cda8553b069cc27b72ba5f924774b1be49c7\ ce55f82ce046a86b29b85bca062f1a52ac1a99ff0621b1288609d82e4c859fbb8a2d\ 98533268a218e3abb345347676fac41f57990e151cfe5b142d44864be22ec04c8123\ 954d1e0263d1846ec44814f765ad14b95a46281c92cccd47aaab9f7420419742fcf9\ 3be2a58f265a5b30886cfb2b474ea6618bb465b8851e0cc96339234c34cc3b9e17ba\ 95ca3ad6c4838ab2b87de605a82723322a0bdf28a93c99165a5577d4c33d8b369719\ 2521ae835d024c0c08369480f58dffc75eed9a4d4c872773793921c520d6a7b43f69\ 986f0c0990f0cae62295b1ca9d261300e7050ae9b3ba55bb250c92217c8a776b8b5e\ Reddy, et al. Expires 14 November 2026 [Page 72] Internet-Draft COSE HPKE PQ May 2026 b3514588342dad306dcfbbc900c33c24a044cbc9c848c7ca33d651bb717ffd4bc316\ 6b24bdd97e60c759e52c42b780781e765b77ab7f3335865d9a05a8eb9a3c420bce17\ 1e9cd1a453195d2307c833d50a55e1ae60136b38dc9e7ff06e0a98c62c253447056b\ 0091312e3a203bfba42b68a91ccb80fde001fd834469081aaca41bf99a688eb519b7\ c5cc4853367404c84c61ce22b9240501662301d07c247dd9fc26cf56334465211d74\ 5f8d0185db7839bbf20423fc0f0a898f01013787e85a8c003d6d5c62918726810c94\ 6ff1175f345d25e5580b58c559a32247a4705fa4ac3fe7c188823193b7548406345d\ 7949819a24d8f5312ee22aae85745f8036559319426a1a140bb7e428a049ea379172\ 96d54914e8a18a610380d390a7b1527b2662768622615df14fe198bbef149017b4a8\ c50b22e4fab3ba0940da483631192ad1f0b61f1196a1539eef25814c402f96f107bd\ b828de5ba9f0c502b29a448da42025b2453a295ba6257b6ca247fd20a40df13d2ea5\ 142de3b291757cb69691b5e7b04dd650cc98952d590ba6f42554942a1a829b0bc717\ 0fd5243c02410fb01212fbc1612aa548c232707ba7259764cddb86bc93be3bd89596\ 6b608ac4b9c29c7cdab7ba233813d5bb2788110263897e005b37eedb83849650a7c9\ 0eba547889c09c7a6c84ccc72220b234322101ff8b2469798563f9ba89fcb53cbb3f\ 1024595db5a661164ee93a6206550380b4a2c2055255421bc80c4becb3a255943cff\ 9abfc48788b3252a62471e70649d52c79cecc2489d84253c9293ed6b25300017df39\ 7da38b9bb776815d37bca52579bb374d54548bf2b29e775956c390644f9aa2252632\ d04bc37a663b314791829c27b720c51d1483f7e12cd4e7c1f38b6ad98a5e1c147683\ 51a76da1267e529bfb7bb6d1e07d49086b1e893b93097f3920849ba10b8dfb08d6b9\ b15dbc65fda93e004319fe1bbbe4ccab73e00335f6167b1991259156b426355491c1\ 1a32956fc798f6ea73c363c8d5b371d4200891342d60e09b8b79cadc415281d56e75\ 930045b2203d1717d420ae9c58047d38119bf97111caba42471ae7d25c7d64c01784\ 8e741a22f23427fb2a135fcb99acbaaa1f68021d4b9367c0389c150b81207c67bb1b\ 74d07f94e7729ffcab169002004025eda27a31685bfad3c227c05287b430d72a425b\ 355785549c45e83db6d90bd2c306632c912390767607a960985530bc2c4002207697\ c21921224d64acd93a4ba558b4ce7c30f503c849021ada958df07b793d25be8b279f\ 55d3180e8b03cdb3a842b60dc1576107f93a32189f2a928eaf302841960a77083492\ b295edfb64abba50fbd31ce47a308cc9837cb865b440091ed56d6f3cb79e7608d3e2\ 788006b9887b36e940bd2101002c59361b1c7cf243b708fbb74afc462bccc3fa396b\ 82f31f7d5344c60a629aa821373c9084f312c3601e03c539fdfa45f5c6cdd14409c7\ bb7a82613573b9247a93404d179c11e7ac76bbca925cb1b916b323818beea94a1d4c\ a492d4c1c1041f84da3f54c540ac6494fe08ccf9569620427179f3099d016c82a434\ 00bbc102cc741c22b539c52422e59a69f71c2b6c8abfa56f7fdc32b6e9718979270e\ 484c57b81359829cb8758360026a7b3a8195657acaf1865a41aa5aabaaec7c323d8f\ ae01355bbbc99d2b3fc7dac82661d42158404cae5ae552c32ce31cc6c60d4b8f6f1a\ 36b034c325d016e6f38e8f3d5c0f00a32f6b0990170c15043f8eb6137e2eb1965ba7\ fe7768f3fd194872748f85c920e4 Figure 46: HPKE-13-KE COSE_Key (Hex-Encoded CBOR) NOTE: '\' line wrapping per RFC 8792 / COSE_Encrypt / 96([ / protected / h'a10103', / unprotected / { / iv / 5: h'5edd2f32c88a7ed5084ba5e9' }, Reddy, et al. Expires 14 November 2026 [Page 73] Internet-Draft COSE HPKE PQ May 2026 / ciphertext / h'a89e91fbc720130044ea756b46c459be83a87b4ddf5d71e82\ e60131ecd374d81ede7a955b473e45874af6f8624813cc37d33d6dee98cde887\ a898f12263444f2eb0d01295a46e406b5e7474879163fa93f6ff3d053ab2c87f\ 84bbd8712aa6b31ee6d3207c792ef8c25990e64d2606712523e5c4bd5a0e8573\ bf244255b2fa82cde8662a2dc93a334c1eba037e8ef86647632aab02bd883c4f\ f8cdbc94086e12d28584508132b6f84423b4a3fd46149ac44fbf6eb9ef7d057d\ 9d3f9c170767d66afc7d1215b7d1f24acfc99f2f42e7db065672200235149808\ fecb682f101b8526de33bc89099cfff488fae35a7eba7f254814293937318466\ afac175a37be0cf2d08d9a113bcbaf7ac034a44bf2b3e7b2e9983ea682128910\ a30c60010e0c84331', / recipients / [ [ / protected / h'a20118410458201b28d7cad6a4ba7cdfceac81643186b3\ b4853d872f0d35e427b8fe98260ef2a6', / unprotected / { / ek / -4: h'7649b0acc2ecaa9725a3afddb317645725a4628cac13380\ e56983ed07f545ef9c54d551e7bf990fe66ae902498e38ee50ca825eacfd0f84\ 3a2f1c1ff6585d46d14e019361e757ab65f031b00d3cd1b20a7c929579d37ed6\ af700fb3718b129376fa00ab6a91f6d4dc08218fcc5c061329d3d18737132cba\ a3157edd2afabc8a169c7649c19da9f751fff11298bab658584e8166dd4b0e07\ 0f23807e74604e002dcf57b26c61503188bdeed680f937e9bdd24121c5126fa9\ 63cad99dde48a04dee29494860d6fa3b1709a00c13ee127f51e2ad73c2ad840f\ f33f93eee3b5ed2176c87c6314f7e98ee5b0e265576e967875f20c120fbb59a8\ 0ffa3df20e364b1ab5f68b76c2baa95e336a45e977413d97d7227e3777587797\ cf5552749e1e5943dbadd71f3dd9d959b3530e67611cf0c3f4f17759302cc796\ e0a7620cb759210b8d97b07dbb4d56cbb35dbd14c57d3936dbae0ae4ab624b15\ 0903f29250991da9f8c10dc3da1bc584a61c7c455c9164cd3ab5d0453eed9a8b\ e4bb1f8cc5dc5fb9243b218b685a93d4466af77c4925a6803edae64f9b584d93\ 2e07771511458913cc6c35e54468242a89a53d1f1bdeb0f3107cc99959d5668d\ 3c4b13c537a0897baa295506ec786fc0ce0a1f669b39f6d79cba0901ea79e0c4\ b005491be47a52f0147bb406b289d656e379c6eb69b20cdcb426eb8af207ba58\ 64d304e90336e034e87415224a34d95d9cf1206cb0c0d063362b36981c820b0c\ ff56f81e46b0b2823a108ca1b413e063eb7af17e86ec42a481d07817325a7c91\ 7fbc12790a8dc0fdfa7f5fba208bf308e0cf31a96b3d5406e65db00b58cd4b65\ 9cc46ae8ca15542534e3a3f30ef69b4c8c435ec0c7b56cc0ee6130d0e5beeeb3\ 3c3683befd7c6bf882d72fb02b2f82e7d68da3f36404ddd3e6e1b3270fe4ec7a\ c72bfb661a672c13f2b253acab4fbc9cead329f32edbd540f45b5dec3d76411a\ 6cdbcc3ceea277e32f51b540ef7fd188db51ace93461e7c1e68ef17defdc6301\ 52f7464f6a801ee4faa5a61fd88334d08013e2ef01743eaf88ad89f557d12821\ 4a22e44333643539b21a7477bc2f91b5441087247070b9fa96ce70f6508256d5\ 868fd5a8d5082aee432a9882afc4d63389b05470ea02099ceaebe86b5b15f019\ 9106aa085ff9608a1bf1ad19e6f4f7677c1bbad03fd17b9c3696f8e6b233faa4\ 3b73e6e501d7b48e7f02a4d235352d2c1da56082778638971e128e34eff4a4ae\ 40e745fa232990440d3c3eaac4679730e6eb15d06d3078807c82f20c79af301f\ f251420f75f44193e2b41a267de3fde14d95b6940950b548f2be7167be1b1f21\ 3fbd3d03a04bc238889c683788c79442a4288ee2ed9c386b034d2337d1daa06c\ c287835c8901f75977cdbbe196ff6f8fafed48c332ce6d0a6c80bf4a61aa37b6\ 56902893af189757f8701945cf72fd53f5b13a760af59395186f243e8e300227\ Reddy, et al. Expires 14 November 2026 [Page 74] Internet-Draft COSE HPKE PQ May 2026 d96b50ff6afed9dfe3cbb94119a403bf48680eac959c7aab8054b71f3796b977\ a48198cc765ffb0f619e5f2eaad20c0a35ded23fcc3069adb090ee72c719b9cc\ 69059a88573f241f5b10ed0c3a81905a8de8e69f1fb4bfca3c7eaf31df7269c4\ a9c865a293c98e8533859390caab3b73f0a1bcacf6aea39402b64d88c9feeb93\ 1e7e5fa6bbfb852139ebfec068734e8fab63c2c766f591a95c3ca6301a11bfc2\ f9b8c8b06dc1390635c4f327672e967145370126748e831d12812480430b9635\ 4059cb879e8112d2e52262cde0bf7546e02e557f9c95b0572e8b9d250c82901d\ b2ca02b107304be196184e2901603f302bb2270e32da6beccfb6a15ede48b6af\ 5c336d60750fe26ff9f6d5f91aebe3ba8e88a811bf496325f13ef2630cb467c6\ 019cb7a03cd5df5a3b08b2272914a06b7958919a7f86d0c3082536843202998e\ 63bb8e66b74802b08fb0c54ad8e117a4c65f8de46ee159d73ccec523a4a4a695\ 03a684c29bd47dede6b73ebbbaa57baa844a90a7786496bcb4cdd111f2efaed9\ c580409a6c4e521b00caedb45f0e5efb45ce71a0f046af6d4917aa098554f369\ a138a1e381d52b18081acce71292a79c23fa350b8117edc2a0cc45729d0fc0b2\ bd718e5997c9e9020a8d8b555d8bbaed335af7bc8978547c6dda823004e5efa2\ da88439fc1c44c3ebc9709c8d9c45de41b6562fac35b14b568610a10c17253b6\ f72417424d601c1eb' }, / ciphertext / h'3189523afc770f72fd8c287e0e58d1a17f4f43a3c035d\ 16474e06b1ac66e9c645adff5b2103e086fa767544acbc85adb' ] ] ]) Figure 47: HPKE-13-KE COSE_Encrypt (Diagnostic Notation) NOTE: '\' line wrapping per RFC 8792 d8608443a10103a1054c5edd2f32c88a7ed5084ba5e9590121a89e91fbc720130044\ ea756b46c459be83a87b4ddf5d71e82e60131ecd374d81ede7a955b473e45874af6f\ 8624813cc37d33d6dee98cde887a898f12263444f2eb0d01295a46e406b5e7474879\ 163fa93f6ff3d053ab2c87f84bbd8712aa6b31ee6d3207c792ef8c25990e64d26067\ 12523e5c4bd5a0e8573bf244255b2fa82cde8662a2dc93a334c1eba037e8ef866476\ 32aab02bd883c4ff8cdbc94086e12d28584508132b6f84423b4a3fd46149ac44fbf6\ eb9ef7d057d9d3f9c170767d66afc7d1215b7d1f24acfc99f2f42e7db06567220023\ 5149808fecb682f101b8526de33bc89099cfff488fae35a7eba7f254814293937318\ 466afac175a37be0cf2d08d9a113bcbaf7ac034a44bf2b3e7b2e9983ea682128910a\ 30c60010e0c8433181835827a20118410458201b28d7cad6a4ba7cdfceac81643186\ b3b4853d872f0d35e427b8fe98260ef2a6a1235906207649b0acc2ecaa9725a3afdd\ b317645725a4628cac13380e56983ed07f545ef9c54d551e7bf990fe66ae902498e3\ 8ee50ca825eacfd0f843a2f1c1ff6585d46d14e019361e757ab65f031b00d3cd1b20\ a7c929579d37ed6af700fb3718b129376fa00ab6a91f6d4dc08218fcc5c061329d3d\ 18737132cbaa3157edd2afabc8a169c7649c19da9f751fff11298bab658584e8166d\ d4b0e070f23807e74604e002dcf57b26c61503188bdeed680f937e9bdd24121c5126\ fa963cad99dde48a04dee29494860d6fa3b1709a00c13ee127f51e2ad73c2ad840ff\ 33f93eee3b5ed2176c87c6314f7e98ee5b0e265576e967875f20c120fbb59a80ffa3\ df20e364b1ab5f68b76c2baa95e336a45e977413d97d7227e3777587797cf5552749\ e1e5943dbadd71f3dd9d959b3530e67611cf0c3f4f17759302cc796e0a7620cb7592\ Reddy, et al. Expires 14 November 2026 [Page 75] Internet-Draft COSE HPKE PQ May 2026 10b8d97b07dbb4d56cbb35dbd14c57d3936dbae0ae4ab624b150903f29250991da9f\ 8c10dc3da1bc584a61c7c455c9164cd3ab5d0453eed9a8be4bb1f8cc5dc5fb9243b2\ 18b685a93d4466af77c4925a6803edae64f9b584d932e07771511458913cc6c35e54\ 468242a89a53d1f1bdeb0f3107cc99959d5668d3c4b13c537a0897baa295506ec786\ fc0ce0a1f669b39f6d79cba0901ea79e0c4b005491be47a52f0147bb406b289d656e\ 379c6eb69b20cdcb426eb8af207ba5864d304e90336e034e87415224a34d95d9cf12\ 06cb0c0d063362b36981c820b0cff56f81e46b0b2823a108ca1b413e063eb7af17e8\ 6ec42a481d07817325a7c917fbc12790a8dc0fdfa7f5fba208bf308e0cf31a96b3d5\ 406e65db00b58cd4b659cc46ae8ca15542534e3a3f30ef69b4c8c435ec0c7b56cc0e\ e6130d0e5beeeb33c3683befd7c6bf882d72fb02b2f82e7d68da3f36404ddd3e6e1b\ 3270fe4ec7ac72bfb661a672c13f2b253acab4fbc9cead329f32edbd540f45b5dec3\ d76411a6cdbcc3ceea277e32f51b540ef7fd188db51ace93461e7c1e68ef17defdc6\ 30152f7464f6a801ee4faa5a61fd88334d08013e2ef01743eaf88ad89f557d128214\ a22e44333643539b21a7477bc2f91b5441087247070b9fa96ce70f6508256d5868fd\ 5a8d5082aee432a9882afc4d63389b05470ea02099ceaebe86b5b15f0199106aa085\ ff9608a1bf1ad19e6f4f7677c1bbad03fd17b9c3696f8e6b233faa43b73e6e501d7b\ 48e7f02a4d235352d2c1da56082778638971e128e34eff4a4ae40e745fa232990440\ d3c3eaac4679730e6eb15d06d3078807c82f20c79af301ff251420f75f44193e2b41\ a267de3fde14d95b6940950b548f2be7167be1b1f213fbd3d03a04bc238889c68378\ 8c79442a4288ee2ed9c386b034d2337d1daa06cc287835c8901f75977cdbbe196ff6\ f8fafed48c332ce6d0a6c80bf4a61aa37b656902893af189757f8701945cf72fd53f\ 5b13a760af59395186f243e8e300227d96b50ff6afed9dfe3cbb94119a403bf48680\ eac959c7aab8054b71f3796b977a48198cc765ffb0f619e5f2eaad20c0a35ded23fc\ c3069adb090ee72c719b9cc69059a88573f241f5b10ed0c3a81905a8de8e69f1fb4b\ fca3c7eaf31df7269c4a9c865a293c98e8533859390caab3b73f0a1bcacf6aea3940\ 2b64d88c9feeb931e7e5fa6bbfb852139ebfec068734e8fab63c2c766f591a95c3ca\ 6301a11bfc2f9b8c8b06dc1390635c4f327672e967145370126748e831d128124804\ 30b96354059cb879e8112d2e52262cde0bf7546e02e557f9c95b0572e8b9d250c829\ 01db2ca02b107304be196184e2901603f302bb2270e32da6beccfb6a15ede48b6af5\ c336d60750fe26ff9f6d5f91aebe3ba8e88a811bf496325f13ef2630cb467c6019cb\ 7a03cd5df5a3b08b2272914a06b7958919a7f86d0c3082536843202998e63bb8e66b\ 74802b08fb0c54ad8e117a4c65f8de46ee159d73ccec523a4a4a69503a684c29bd47\ dede6b73ebbbaa57baa844a90a7786496bcb4cdd111f2efaed9c580409a6c4e521b0\ 0caedb45f0e5efb45ce71a0f046af6d4917aa098554f369a138a1e381d52b18081ac\ ce71292a79c23fa350b8117edc2a0cc45729d0fc0b2bd718e5997c9e9020a8d8b555\ d8bbaed335af7bc8978547c6dda823004e5efa2da88439fc1c44c3ebc9709c8d9c45\ de41b6562fac35b14b568610a10c17253b6f72417424d601c1eb58303189523afc77\ 0f72fd8c287e0e58d1a17f4f43a3c035d16474e06b1ac66e9c645adff5b2103e086f\ a767544acbc85adb Figure 48: HPKE-13-KE COSE_Encrypt (Hex-Encoded CBOR) Acknowledgments Thanks to Ilari Liusvaara and Orie Steele for the discussion and comments. Reddy, et al. Expires 14 November 2026 [Page 76] Internet-Draft COSE HPKE PQ May 2026 Document History draft-reddy-cose-hpke-pq-pqt-03 * Folded long test-vector lines using the RFC 8792 single backslash strategy draft-reddy-cose-hpke-pq-pqt-02 * Added rationale for retaining ML-KEM-512-based ciphersuites for COSE * Added a note that HPKE algorithm numbering is intentionally aligned with the companion JOSE registrations draft-reddy-cose-hpke-pq-pqt-00 * Replaces draft-reddy-cose-jose-pqc-hybrid-hpke * Removed ChaCha20Poly1305 AEAD ciphersuites * Adapted source from draft-skokan-jose-hpke-pq-pqt-04 for COSE * Added Filip Skokan as author Authors' Addresses Tirumaleswar Reddy Nokia Email: k.tirumaleswar_reddy@nokia.com Hannes Tschofenig University of the Bundeswehr Munich Email: hannes.tschofenig@gmx.net Filip Skokan Okta Email: panva.ip@gmail.com Reddy, et al. Expires 14 November 2026 [Page 77]