JunHyuk Song Jicheol Lee INTERNET DRAFT Samsung Electronics Expires: November 30, 2005 May 31 2005 The AES-CMAC-PRF-128 Algorithm for the Internet Key Exchange Protocol (IKE) draft-songlee-aes-cmac-prf-128-00.txt Status of This Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Copyright Notice Copyright (C) The Internet Society (2005). Abstract Some implementations of IP Security (IPsec) may want to use a pseudo-random function derived from the Advanced Encryption Standard (AES). This memo describes such an algorithm, called AES-CMAC- PRF-128. Song and Lee. Expires November 2005 [Page 1] Internet Draft May 2005 1. Introduction [AES-CMAC] describes a method to use the Advanced Encryption Standard (AES) as a message authentication code (MAC) whose output is 128 bits long. 128 bits output is useful as a long-lived pseudo-random (PRF) in either IKE version 1 or version 2. Both versions of IKE use the PRF to create keys in a fashion that is dependent on the length of the output of the PRF. This memo specify AES-CMAC use as a PRF whose output is 128 bits, named AES-CMAC-PRF-128. 2. The AES-CMAC-PRF-128 Algorithm The AES-CMAC-PRF-128 algorithm is identical to AES-CMAC defined in [AES-CMAC]. The test vectors in appendix of [AES-CMAC] can be used for AES-CMAC-PRF-128 as well. 3. Security Considerations The security provided by AES-CMAC-PRF-128 is based upon the strength of AES. At the time of this writing, there are no known practical cryptographic attacks against AES or AES-CMAC-PRF-128. As is true with any cryptographic algorithm, part of its strength lies in the security of the key management mechanism, the strength of the associated secret key, and upon the correctness of the implementations in all of the participating systems. [AES-CMAC] contains test vectors to assist in verifying the correctness of the AES-CMAC-PRF-128 code. 4. Acknowledgement Portions of this text were borrowed from [AES-XCBC-MAC]. 5. References [AES-CMAC] JunHyuk Song and Jicheol Lee, "The AES-CMAC Algorithm," draft-songlee-aes-cmac-01.txt, May 2005. [AES-XCBC-MAC] P. Hoffman, "The AES-XCBC-PRF-128 Algorithm for the Internet Key Exchange Protocol (IKE)," RFC3664, Jan 2004. Song and Lee. Expires November 2005 [Page 2] Internet Draft May 2005 Author's Address Junhyuk Song Samsung Electronics +82-31-279-3639 santajunman@hanafos.com Jicheol Lee Samsung Electronics +82-31-279-3605 jicheol.lee@samsung.com Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. 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Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Song and Lee. Expires November 2005 [Page 3] Internet Draft May 2005 Copyright Statement Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Song and Lee. Expires November 2005 [Page 4]