Network Working Group H.J. Lee Request for Comments: 4162 J.H. Yoon Category: Standards Track J.I. Lee KISA August 2005
Addition of SEED 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 SEED encryption algorithm as a bulk cipher algorithm.
SEED is a symmetric encryption algorithm that was developed by Korea Information Security Agency (KISA) and a group of experts, beginning in 1998. The input/output block size of SEED is 128-bit and the key length is also 128-bit. SEED has the 16-round Feistel structure. A 128-bit input is divided into two 64-bit blocks and the right 64-bit block is an input to the round function with a 64-bit subkey generated from the key scheduling.
Lee, et al. Standards Track [Page 1]
RFC 4162 SEED Cipher Suites to TLS August 2005
SEED is easily implemented in various software and hardware because it is designed to increase the efficiency of memory storage and the simplicity of generating keys without degrading the security of the algorithm. In particular, it can be effectively adopted in a computing environment that has a restricted resources such as mobile devices, smart cards, and so on.
SEED is a national industrial association standard [TTASSEED] and is widely used in South Korea for electronic commerce and financial services operated on wired & wireless PKI.
The algorithm specification and object identifiers are described in [SEED-ALG]. The SEED homepage, http://www.kisa.or.kr/seed/seed_eng.html, contains a wealth of information about SEED, including detailed specification, evaluation report, test vectors, and so on.
It is not believed that the new cipher suites are less secure than the corresponding older ones. No security problem has been found on SEED. SEED is robust against known attacks, including differential cryptanalysis, linear cryptanalysis, and related key attacks, etc. SEED has gone through wide public scrutinizing procedures. Especially, it has been evaluated and also considered cryptographically secure by trustworthy organizations such as ISO/IEC JTC 1/SC 27 and Japan CRYPTREC (Cryptography Research and Evaluation Committees) [ISOSEED] [CRYPTREC]. SEED has been submitted to several other standardization bodies such as ISO (ISO/IEC 18033-3) and IETF S/MIME Mail Security [SEED-SMIME]; and it is under consideration. For further security considerations, the reader is encouraged to read [SEED-EVAL].
For other security considerations, please refer to the security of the corresponding older cipher suites described in [TLS] and [AES-TLS].
[ISOSEED] ISO/IEC JTC 1/SC 27, "National Body contributions on NP 18033 'Encryption Algorithms' in Response to SC 27 N2563 (ATT.3 Korea Contribution)", ISO/IEC JTC 1/SC 27 N2656r1 (n2656_3.zip), October 2000.
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