Remote ATtestation ProcedureS (rats) Internet Drafts

 The Entity Attestation Token (EAT)
 Date: 10/07/2022
 Authors: Laurence Lundblade, Giridhar Mandyam, Jeremy O'Donoghue
 Working Group: Remote ATtestation ProcedureS (rats)
 Formats: xml pdf txt html
An Entity Attestation Token (EAT) provides an attested claims set that describes state and characteristics of an entity, a device like a phone, IoT device, network equipment or such. This claims set is used by a relying party, server or service to determine how much it wishes to trust the entity. An EAT is either a CBOR Web Token (CWT) or JSON Web Token (JWT) with attestation-oriented claims. To a large degree, all this document does is extend CWT and JWT.
 Remote Attestation Procedures Architecture
 Date: 28/07/2022
 Authors: Henk Birkholz, Dave Thaler, Michael Richardson, Ned Smith, Wei Pan
 Working Group: Remote ATtestation ProcedureS (rats)
 Formats: html xml txt
In network protocol exchanges it is often useful for one end of a communication to know whether the other end is in an intended operating state. This document provides an architectural overview of the entities involved that make such tests possible through the process of generating, conveying, and evaluating evidentiary claims. An attempt is made to provide for a model that is neutral toward processor architectures, the content of claims, and protocols.
 A YANG Data Model for Challenge-Response-based Remote Attestation Procedures using TPMs
 Date: 18/05/2022
 Authors: Henk Birkholz, Michael Eckel, Shwetha Bhandari, Eric Voit, Bill Sulzen, Liang Xia, Tom Laffey, Guy Fedorkow
 Working Group: Remote ATtestation ProcedureS (rats)
 Formats: xml html txt
This document defines YANG RPCs and a few configuration nodes required to retrieve attestation evidence about integrity measurements from a device, following the operational context defined in TPM-based Network Device Remote Integrity Verification. Complementary measurement logs are also provided by the YANG RPCs, originating from one or more roots of trust for measurement (RTMs). The module defined requires at least one TPM 1.2 or TPM 2.0 as well as a corresponding TPM Software Stack (TSS), or equivalent hardware implementations that include the protected capabilities as provided by TPMs as well as a corresponding software stack, included in the device components of the composite device the YANG server is running on.
 TPM-based Network Device Remote Integrity Verification
 Date: 22/03/2022
 Authors: Guy Fedorkow, Eric Voit, Jessica Fitzgerald-McKay
 Working Group: Remote ATtestation ProcedureS (rats)
 Formats: txt html xml
This document describes a workflow for remote attestation of the integrity of firmware and software installed on network devices that contain Trusted Platform Modules [TPM1.2], [TPM2.0], as defined by the Trusted Computing Group (TCG)), or equivalent hardware implementations that include the protected capabilities, as provided by TPMs.
 A CBOR Tag for Unprotected CWT Claims Sets
 Date: 11/07/2022
 Authors: Henk Birkholz, Jeremy O'Donoghue, Nancy Cam-Winget, Carsten Bormann
 Working Group: Remote ATtestation ProcedureS (rats)
 Formats: txt html xml
CBOR Web Token (CWT, RFC 8392) Claims Sets sometimes do not need the protection afforded by wrapping them into COSE, as is required for a true CWT. This specification defines a CBOR tag for such unprotected CWT Claims Sets (UCCS) and discusses conditions for its proper use.
 Attestation Event Stream Subscription
 Date: 07/03/2022
 Authors: Henk Birkholz, Eric Voit, Wei Pan
 Working Group: Remote ATtestation ProcedureS (rats)
 Formats: xml html txt
This memo defines how to subscribe to YANG Event Streams for Remote Attestation Procedures (RATS). In RATS, Conceptional Messages, are defined. Analogously, the YANG module defined in this memo augments the YANG module for TPM-based Challenge-Response based Remote Attestation (CHARRA) to allow for subscription to remote attestation Evidence. Additionally, this memo provides the methods and means to define additional Event Streams for other Conceptual Message as illustrated in the RATS Architecture, e.g. Attestation Results, Endorsements, or Event Logs.
 Direct Anonymous Attestation for the Remote Attestation Procedures Architecture
 Date: 10/07/2022
 Authors: Henk Birkholz, Christopher Newton, Liqun Chen, Dave Thaler
 Working Group: Remote ATtestation ProcedureS (rats)
 Formats: txt html xml
This document maps the concept of Direct Anonymous Attestation (DAA) to the Remote Attestation Procedures (RATS) Architecture. The role DAA Issuer is introduced and its interactions with existing RATS roles is specified.
 Attestation Results for Secure Interactions
 Date: 07/03/2022
 Authors: Eric Voit, Henk Birkholz, Thomas Hardjono, Thomas Fossati, Vincent Scarlata
 Working Group: Remote ATtestation ProcedureS (rats)
 Formats: txt html xml
This document defines reusable Attestation Result information elements. When these elements are offered to Relying Parties as Evidence, different aspects of Attester trustworthiness can be evaluated. Additionally, where the Relying Party is interfacing with a heterogeneous mix of Attesting Environment and Verifier types, consistent policies can be applied to subsequent information exchange between each Attester and the Relying Party.

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Remote ATtestation ProcedureS (rats)

WG Name Remote ATtestation ProcedureS
Acronym rats
Area Security Area (sec)
State Active
Charter charter-ietf-rats-02 Approved
Document dependencies
Additional resources Issue tracker, Wiki, Zulip Stream
Personnel Chairs Kathleen Moriarty, Nancy Cam-Winget, Ned Smith
Area Director Roman Danyliw
Mailing list Address
To subscribe
Chat Room address

Charter for Working Group

# Introduction

In network protocol exchanges, it is often the case that one entity (a Relying Party) requires evidence about the remote peer (and system components [RFC4949] thereof), in order to assess the trustworthiness of the peer. Remote attestation procedures (RATS) determine whether relying parties can establish a level of confidence in the trustworthiness of remote peers, called Attesters. The objective is achieved by a two-stage appraisal procedure facilitated by a trusted third party, called Verifier, with trusted links to the supply chain.

The procedures for the two stages are:

* Evidence Appraisal: a Verifier applies policy and supply chain input, such as Endorsements and References Values, to create Attestation Results from Evidence.

* Attestation Results Appraisal: a Relying Party applies policy to Attestation Results associated with an Attester's Evidence that originates from a trusted Verifier. The results are trust decisions regarding the Attester.

To improve the confidence in a system component's trustworthiness, a relying party may require evidence about:

* system component identity,
* composition of system components, including nested components,
* roots of trust,
* an assertion/claim origination or provenance,
* manufacturing origin,
* system component integrity,
* system component configuration,
* operational state and measurements of steps which led to the operational state, or

* other factors that could influence trust decisions.

While domain-specific attestation mechanisms such as Trusted Computing Group (TCG) Trusted Platform Module (TPM)/TPM Software Stack (TSS), Fast Identity Online (FIDO) Alliance attestation, and Android Keystore attestation exist, there is no interoperable way to create and process attestation evidence to make determinations about system components among relying parties of different manufactures and origins.

# Goals

The WG has defined an architecture (draft-ietf-rats-architecture) for remote attestation. The WG will standardize formats for describing evidence and attestation results and the associated procedures and protocols to convey evidence for appraisal to a verifier and attestation results to a relying party. Additionally, the WG will standardize formats for endorsements and reference values, and may apply and/or profile existing protocols (e.g., DTLS, CoAP, or MUD) to convey them to the verifier. Formats and protocols for appraisal policy for evidence and appraisal policy for attestation results are out of scope.

The WG will continue to cooperate and coordinate with other IETF WGs such as TEEP, SUIT, CoRE, ACE, and CBOR; and work with organizations in the community, such as the TCG, Global Platform, and the FIDO Alliance, as appropriate.

# Program of Work

The working group will develop standards supporting interoperable remote attestation procedures for system components. The main deliverables are as follows:

1. Specify use cases for remote attestation (to document and achieve WG consensus but not expected to be published as an RFC).

2. Specify augmentations to the RATS architecture (draft-ietf-rats-architecture) in support of specific attestation techniques.

3. Standardize an information model for evidence and attestations results scoped by the specified use-cases.

4. Standardize data models that implement and secure the defined information model (e.g., CBOR Web Token structures [RFC8392], JSON Web Token structures [RFC7519]).

5. If feasible, use or extend existing protocols to securely convey evidence and attestation results, or if not, then standardize interoperable protocols for this purpose.

6. Standardize interoperable data formats to securely declare and convey endorsements and reference values.


Date Milestone Associated documents
Nov 2023 Submit Concise Reference Integrity and Endorsement Manifests for publication
Jul 2022 Call for adoption on Concise Reference Integrity and Endorsement Manifests