The AES-CMAC-96 Algorithm and Its Use with IPsec
RFC 4494
Document | Type |
RFC - Proposed Standard
(June 2006; No errata)
Was draft-songlee-aes-cmac-96 (individual in sec area)
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Authors | Junhyuk Song , Radha Poovendran , Jicheol Lee | ||
Last updated | 2015-10-14 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4494 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Russ Housley | ||
Send notices to | santajunman@hanafos.com |
Network Working Group JH. Song Request for Comments: 4494 R. Poovendran Category: Standards Track University of Washington J. Lee Samsung Electronics June 2006 The AES-CMAC-96 Algorithm and Its Use with IPsec Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2006). Abstract The National Institute of Standards and Technology (NIST) has recently specified the Cipher-based Message Authentication Code (CMAC), which is equivalent to the One-Key CBC-MAC1 (OMAC1) algorithm submitted by Iwata and Kurosawa. OMAC1 efficiently reduces the key size of Extended Cipher Block Chaining mode (XCBC). This memo specifies the use of CMAC mode on the authentication mechanism of the IPsec Encapsulating Security Payload (ESP) and the Authentication Header (AH) protocols. This new algorithm is named AES-CMAC-96. Song, et al. Standards Track [Page 1] RFC 4494 The AES-CMAC Algorithm and IPsec June 2006 1. Introduction The National Institute of Standards and Technology (NIST) has recently specified the Cipher-based Message Authentication Code (CMAC). CMAC [NIST-CMAC] is a message authentication code that is based on a symmetric key block cipher such as the Advanced Encryption Standard [NIST-AES]. CMAC is equivalent to the One-Key CBC MAC1 (OMAC1) submitted by Iwata and Kurosawa [OMAC1a, OMAC1b]. OMAC1 is an improvement of the eXtended Cipher Block Chaining mode (XCBC) submitted by Black and Rogaway [XCBCa, XCBCb], which itself is an improvement of the basic CBC-MAC. XCBC efficiently addresses the security deficiencies of CBC-MAC, and OMAC1 efficiently reduces the key size of XCBC. This memo specifies the usage of CMAC on the authentication mechanism of the IPsec Encapsulating Security Payload [ESP] and Authentication Header [AH] protocols. This new algorithm is named AES-CMAC-96. For further information on AH and ESP, refer to [AH] and [ROADMAP]. 2. Basic Definitions CBC Cipher Block Chaining mode of operation for message authentication code. MAC Message Authentication Code. A bit string of a fixed length, computed by the MAC generation algorithm, that is used to establish the authority and, hence, the integrity of a message. CMAC Cipher-based MAC based on an approved symmetric key block cipher, such as the Advanced Encryption Standard. Key (K) 128-bit (16-octet) key for AES-128 cipher block. Denoted by K. Message (M) Message to be authenticated. Denoted by M. Length (len) The length of message M in octets. Denoted by len. The minimum value is 0. The maximum value is not specified in this document. truncate(T,l) Truncate T (MAC) in most-significant-bit-first (MSB-first) order to a length of l octets. T The output of AES-CMAC. Song, et al. Standards Track [Page 2] RFC 4494 The AES-CMAC Algorithm and IPsec June 2006 Truncated T The truncated output of AES-CMAC-128 in MSB-first order. AES-CMAC CMAC generation function based on AES block cipher with 128-bit key. AES-CMAC-96 IPsec AH and ESP MAC generation function based on AES-CMAC, which truncates the 96 most significant bits of the 128-bit output. 3. AES-CMAC The core of AES-CMAC-96 is the AES-CMAC [AES-CMAC]. The underlying algorithms for AES-CMAC are the Advanced Encryption Standard cipher block [NIST-AES] and the recently defined CMAC mode of operation [NIST-CMAC]. AES-CMAC provides stronger assurance of data integrity than a checksum or an error detecting code. The verification of a checksum or an error detecting code detects only accidental modifications of the data, while CMAC is designed to detect intentional, unauthorized modifications of the data, as well as accidental modifications. The output of AES-CMAC can validate the input message. Validating the message provides assurance of theShow full document text