TLS Working Group Hyangjin Lee(KISA) INTERNET-DRAFT Jaeho Yoon(KISA) Document: draft-lee-tls-seed-01.txt Jaeil Lee(KISA) Expiration Date: July 2005 January 2005 Addition of SEED Ciphersuites to Transport Layer Security (TLS) Status of this Memo By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, or will be disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. 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 SEED 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 SEED encryption algorithm as a bulk cipher algorithm. Lee, et. al. Expires - July 2005 [Page 1] INTERNET-DRAFT SEED Ciphersuites to TLS January 2005 1.1. SEED SEED is a symmetric encryption algorithm that had been developed by KISA(Korea Information Security Agency) and a group of experts since 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. SEED is easily implemented in various software and hardware because it is designed to increase the efficiency of memory storage and the simplicity in generating keys without degrading the security of the algorithm. In particular, it can be effectively adopted to a computing environment with a restricted resources such as a 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-ID]. 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. 1.2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document (in uppercase, as shown) are to be interpreted as described in [RFC2119]. 2. Proposed Cipher Suites The new ciphersuites proposed here have the following definitions: CipherSuite TLS_RSA_WITH_SEED_CBC_SHA = { 0x00, 0x96}; CipherSuite TLS_DH_DSS_WITH_SEED_CBC_SHA = { 0x00, 0x97}; CipherSuite TLS_DH_RSA_WITH_SEED_CBC_SHA = { 0x00, 0x98}; CipherSuite TLS_DHE_DSS_WITH_SEED_CBC_SHA = { 0x00, 0x99}; CipherSuite TLS_DHE_RSA_WITH_SEED_CBC_SHA = { 0x00, 0x9A}; CipherSuite TLS_DH_anon_WITH_SEED_CBC_SHA = { 0x00, 0x9B}; 3. CipherSuite Definitions Lee, et. al. Expires - July 2005 [Page 2] INTERNET-DRAFT SEED Ciphersuites to TLS January 2005 3.1. Cipher All the ciphersuites described here use SEED in cipher block chaining(CBC) mode as a bulk cipher algorithm. SEED is a 128-bit block cipher with 128-bit key size. 3.2. Hash All the ciphersuites described here use SHA-1 [SHA-1] in an HMAC construction as described in section 5 of [TLS]. 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_SEED_CBC_SHA RSA TLS_DH_DSS_WITH_SEED_CBC_SHA DH_DSS TLS_DH_RSA_WITH_SEED_CBC_SHA DH_RSA TLS_DHE_DSS_WITH_SEED_CBC_SHA DHE_DSS TLS_DHE_RSA_WITH_SEED_CBC_SHA DHE_RSA TLS_DH_anon_WITH_SEED_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. IANA considerations IANA does not currently have a registry for TLS-related numbers, so there are no IANA actions associated with this document. 5. Security Considerations It is not believed that the new ciphersuites are ever 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 other several standardization bodies such as ISO(ISO/IEC 18033-3), IETF S/MIME Mail Security [SEED-SMIME] and it is under consideration. For further security considerations, the reader is encouraged to read [SEED-EVAL]. Lee, et. al. Expires - July 2005 [Page 3] INTERNET-DRAFT SEED Ciphersuites to TLS January 2005 For other security considerations, please refer to the security of the corresponding older ciphersuites described in [TLS] and [AES- TLS]. 6. References 6.1 Normative Reference [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [SEED] KISA, "SEED Algorithm Specification", http://www.kisa.or.kr/seed/seed_eng.html" [TLS] T. Dierks, and C. Allen, "The TLS Protocol Version 1.0", RFC 2246, January 1999. 6.2 Informative Reference [AES-TLS] P. Chown, "Advanced Encryption Standard (AES) Ciphersuites for Transport Layer Security (TLS)", RFC 3268, June 2002. [CRYPTREC] Information-technology Promotion Agency (IPA), Japan, CRYPTREC. "SEED Evaluation Report", February, 2002 http://www.kisa.or.kr/seed/seed_eng.html [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 [SEED-EVAL] KISA, "Self Evaluation Report", http://www.kisa.or.kr/seed/seed_eng.html" [SEED-ID] Jongwook Park, Sungjae Lee, Jeeyeon Kim, Jaeil Lee, "The SEED Encryption Algorithm", draft-park-seed-01.txt, April, 2004. [SEED-SMIME] Jongwook Park, Sungjae Lee, Jeeyeon Kim, Jaeil Lee, "Use of the SEED Encryption Algorithm in CMS", draft-ietf-smime-cms-01.txt, April, 2004. [SHA-1] FIPS PUB 180-1, "Secure Hash Standard", National Institute of Standards and Technology, U.S. Department of Commerce, April 17, 1995. [TTASSEED] Telecommunications Technology Association (TTA), Lee, et. al. Expires - July 2005 [Page 4] INTERNET-DRAFT SEED Ciphersuites to TLS January 2005 South Korea, "128-bit Symmetric Block Cipher (SEED)", TTAS.KO-12.0004, September, 1998 (In Korean) http://www.tta.or.kr/English/new/main/index.htm 7. Authorsí¯ Addresses Hyangjin Lee Korea Information Security Agency Phone: +82-2-405-5446 FAX : +82-2-405-5499 Email: jiinii@kisa.or.kr Jaeho Yoon Korea Information Security Agency Phone: +82-2-405-5434 FAX : +82-2-405-5499 Email: jhyoon@kisa.or.kr Jaeil Lee Korea Information Security Agency Phone: +82-2-405-5300 FAX : +82-2-405-5499 Email: jilee@kisa.or.kr 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. Information on the IETFí¯s procedures with respect to rights in IETF Documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Lee, et. al. Expires - July 2005 [Page 5] INTERNET-DRAFT SEED Ciphersuites to TLS January 2005 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. 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. Lee, et. al. Expires - July 2005 [Page 6]