INTERNET-DRAFT S. Moriai TLS Working Group Nippon Telegraph and Telephone Corporation Expires February 6 2003 August 6 2002 Addition of Camellia Ciphersuites to Transport Layer Security (TLS) <draft-ietf-tls-camellia-02.txt> Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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. Abstract This document proposes the addition of new cipher suites to the Transport Layer Security (TLS) protocol to support the Camellia encryption algorithm as a bulk cipher algorithm. 1. Introduction This document proposes the addition of new cipher suites to the TLS protocol [TLS] to support the Camellia encryption algorithm as a bulk cipher algorithm. This proposal provides a new option for fast, efficient, and royalty-free bulk cipher algorithms. Camellia is a 128-bit block cipher with 128-, 192-, and 256-bit key sizes, i.e. it supports the same block and key sizes as the Advanced Encryption Standard (AES). A description of the Camellia cipher algorithm is in [CamelliaSpec][CamelliaTech]. MORIAI [Page 1]
Internet-Draft Camellia Ciphersuites for TLS August 2002 Efficiency on both software and hardware platforms is a remarkable characteristic of Camellia. In particular, Camellia's small hardware design is suitable for mobile, portable and low power applications. Furthermore, Camellia has withstood extensive cryptanalytic efforts in several open, worldwide cryptographic evaluation projects. 2. Proposed Cipher Suites The new ciphersuites proposed here have the following definitions: CipherSuite TLS_RSA_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x41 }; CipherSuite TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x42 }; CipherSuite TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x43 }; CipherSuite TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x44 }; CipherSuite TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x45 }; CipherSuite TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA = { 0x00,0x46 }; CipherSuite TLS_RSA_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x47 }; CipherSuite TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x48 }; CipherSuite TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x49 }; CipherSuite TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x4A }; CipherSuite TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x4B }; CipherSuite TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA = { 0x00,0x4C }; Note: The above numeric definitions for Cipher Suites have not yet been registered. 3. CipherSuite Definitions 3.1 Cipher All the ciphersuites described here use Camellia in cipher block chaining (CBC) mode as a bulk cipher algorithm. Camellia is a 128-bit block cipher with 128-, 192-, and 256-bit key sizes, i.e. it supports the same block and key sizes as the Advanced Encryption Standard (AES). However, this document only defines ciphersuites for 128- and 256-bit keys as well as AES ciphersuites for TLS [AES]. They are enough for use in efficient and practical cases as well as high-security applications. Key Expanded Effective IV Block Cipher Type Material Key Material Key Bits Size Size CAMELLIA_128_CBC Block 16 16 128 16 16 CAMELLIA_256_CBC Block 32 32 256 16 16 3.2 Hash All the ciphersuites described here use SHA-1 in an HMAC construction as described in section 5 of [TLS], a modified SHA-1 version of the algorithm. MORIAI [Page 2]
Internet-Draft Camellia Ciphersuites for TLS August 2002 3.3 Key exchange The ciphersuites defined here differ in the type of certificate and key exchange method. They use the following options: CipherSuite Key Exchange Algorithm TLS_RSA_WITH_CAMELLIA_128_CBC_SHA RSA TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA DH_DSS TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA DH_RSA TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA DHE_DSS TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA DHE_RSA TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA DH_anon TLS_RSA_WITH_CAMELLIA_256_CBC_SHA RSA TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA DH_DSS TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA DH_RSA TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA DHE_DSS TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA DHE_RSA TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA DH_anon For the meanings of the terms RSA, DH_DSS, DH_RSA, DHE_DSS, DHE_RSA and DH_anon, please refer to sections 7.4.2 and 7.4.3 of [TLS]. 4. Security Considerations It is not believed that the new ciphersuites are ever less secure than the corresponding older ones. Camellia is believed to be secure, and it has withstood extensive cryptanalytic efforts in several open, worldwide cryptographic evaluation projects. For other security considerations, please refer to the security considerations of the corresponding older ciphersuites described in [TLS] and [AES]. 5. Intellectual Property Mitsubishi Electric Corporation (Mitsubishi Electric) and Nippon Telegraph and Telephone Corporation (NTT) have pending applications or filed patents which are essential to Camellia. License policy for these essential patents declared formally by NTT and Mitsubishi Electric is available on the IETF page of Intellectual Property Rights Notices. References [CamelliaSpec] K. Aoki, T. Ichikawa, M. Kanda, M. Matsui, S. Moriai, J. Nakajima, and T. Tokita ``Specification of Camellia - a 128-bit Block Cipher''. http://info.isl.ntt.co.jp/camellia/ MORIAI [Page 3]
Internet-Draft Camellia Ciphersuites for TLS August 2002 [CamelliaTech] K. Aoki, T. Ichikawa, M. Kanda, M. Matsui, S. Moriai, J. Nakajima, and T. Tokita ``Camellia: A 128-Bit Block Cipher Suitable for Multiple Platforms - Design and Analysis -'', In Selected Areas in Cryptography, 7th Annual International Workshop, SAC 2000, August 2000, Proceedings, Lecture Notes in Computer Science 2012, pp.39--56, Springer-Verlag, 2001. [AES] P. Chown, ``Advanced Encryption Standard (AES) Ciphersuites for Transport Layer Security (TLS)'', RFC 3268, June 2002. [TLS] T. Dierks, and C. Allen, ``The TLS Protocol Version 1.0'', RFC 2246, January 1999. Author's Address Shiho Moriai Nippon Telegraph and Telephone Corporation 1-1 Hikarinooka, Yokosuka, 239-0847, Japan Phone: +81-468-59-2007 FAX: +81-468-59-3858 Email: shiho@isl.ntt.co.jp MORIAI [Page 4]
