This document is obsolete. Please
refer to RFC 5932.
Network Working Group S. Moriai Request for Comments: 4132 Sony Computer Entertainment Inc. Category: Standards Track A. Kato NTT Software Corporation M. Kanda Nippon Telegraph and Telephone Corporation July 2005
Addition of Camellia Cipher Suites to Transport Layer Security (TLS)
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 (C) The Internet Society (2005).
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.
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 and efficient bulk cipher algorithms.
Note: This work was done when the first author worked for NTT.
Camellia was selected as a recommended cryptographic primitive by the EU NESSIE (New European Schemes for Signatures, Integrity and Encryption) project [NESSIE] and included in the list of cryptographic techniques for Japanese e-Government systems, which were selected by the Japan CRYPTREC (Cryptography Research and Evaluation Committees) [CRYPTREC]. Camellia is also included in specification of the TV-Anytime Forum [TV-ANYTIME]. The TV-Anytime Forum is an association of organizations that seeks to develop
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RFC 4132 Camellia Cipher Suites for TLS July 2005
specifications to enable audio-visual and other services based on mass-market high-volume digital storage in consumer platforms. Camellia is specified as Cipher Suite in TLS used by Phase 1 S-7 (Bi-directional Metadata Delivery Protection) specification and S-5 (TV-Anytime Rights Management and Protection Information for Broadcast Applications) specification. Camellia has been submitted to other several standardization bodies such as ISO (ISO/IEC 18033) and IETF S/MIME Mail Security Working Group [Camellia-CMS].
Camellia supports 128-bit block size and 128-, 192-, and 256-bit key sizes; i.e., the same interface specifications as the Advanced Encryption Standard (AES) [AES].
Camellia was jointly developed by NTT and Mitsubishi Electric Corporation in 2000 [CamelliaTech]. It was carefully designed to withstand all known cryptanalytic attacks and even to have a sufficiently large security leeway. It has been scrutinized by worldwide cryptographic experts.
Camellia was also designed to be suitable for both software and hardware implementations and to cover all possible encryption applications, from low-cost smart cards to high-speed network systems. Compared to the AES, Camellia offers at least comparable encryption speed in software and hardware. In addition, a distinguishing feature is its small hardware design. Camellia perfectly meets one of the current TLS market requirements, for which low power consumption is mandatory.
The algorithm specification and object identifiers are described in [Camellia-Desc]. The Camellia homepage, http://info.isl.ntt.co.jp/camellia/, contains a wealth of information about camellia, including detailed specification, security analysis, performance figures, reference implementation, and test vectors.
All the cipher suites 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 cipher suites for 128- and 256-bit keys as well as AES cipher suites for TLS [AES-TLS]. These cipher suites are efficient and practical enough for most uses, including high-security applications.
Key Expanded Effective IV Block Cipher Type Material Key Material Key Bits Size Size
It is not believed that the new cipher suites are ever less secure than the corresponding older ones. Camellia is considered secure, and it has withstood extensive cryptanalytic efforts in several open, worldwide cryptographic evaluation projects [CRYPTREC][NESSIE].
At the time of writing this document, there are no known weak keys for Camellia.
For other security considerations, please refer to the security considerations of the corresponding older cipher suites described in [TLS] and [AES-TLS].
[CamelliaTech] Aoki, K., Ichikawa, T., Kanda, M., Matsui, M., Moriai, S., Nakajima, J., and Tokita, T., "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.
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RFC 4132 Camellia Cipher Suites for TLS July 2005
[Camellia-CMS] Moriai, S. and A. Kato, "Use of the Camellia Encryption Algorithm in Cryptographic Message Syntax (CMS)", RFC 3657, January 2004.
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