Network Working Group D. Shaw Internet-Draft November 5, 2007 Updates: 4880 (if approved) Intended status: Standards Track Expires: May 8, 2008 The Camellia Cipher in OpenPGP draft-ietf-openpgp-camellia-00 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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. This Internet-Draft will expire on May 8, 2008. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract This document presents the necessary information to use the Camellia symmetric cipher in the OpenPGP protocol. Shaw Expires May 8, 2008 [Page 1] Internet-Draft The Camellia Cipher in OpenPGP November 2007 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Requirements notation . . . . . . . . . . . . . . . . . . . . . 3 3. Camellia . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 3 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 6. Normative References . . . . . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 4 Intellectual Property and Copyright Statements . . . . . . . . . . 5 Shaw Expires May 8, 2008 [Page 2] Internet-Draft The Camellia Cipher in OpenPGP November 2007 1. Introduction The OpenPGP protocol [RFC4880] can support many different symmetric ciphers. This document presents the necessary information to use the Camellia [RFC3713] symmetric cipher in the OpenPGP protocol. 2. Requirements notation The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 3. Camellia Camellia is specified in [RFC3713]. The symmetric key algorithm number for Camellia with a 256-bit key in OpenPGP is XXXXX [[To be allocated by IANA. Please fill this in - presumably it's 11]]. Note that while Camellia supports 128-bit, 192-bit, and 256-bit keys, the only Camellia key length used for OpenPGP is 256 bits. OpenPGP applications MAY implement Camellia. If implemented, Camellia may be used in any place in OpenPGP where a symmetric cipher is usable, and is subject to the same usage requirements (such as its presence in the Symmetric Algorithm Preferences signature subpacket) as the other symmetric ciphers in OpenPGP. Note that while the OpenPGP algorithm preferences system prevents interoperability problems with public key encrypted messages, if Camellia (or any other optional cipher) is used for encrypting private keys, there could be interoperability problems when migrating a private key from one system to another. A similar issue can arise when using an optional cipher for symmetric-only encrypted messages, as this message type does not perform cipher negotiation. Those using optional ciphers in this way should take care they are using a cipher that their intended recipient can decrypt. 4. Security Considerations At publication time, there are no known weak keys for Camellia, and the Camellia algorithm is believed to be strong. However, as with any technology involving cryptography, implementers should check the current literature, as well as the Camellia home page at , to determine if Camellia has Shaw Expires May 8, 2008 [Page 3] Internet-Draft The Camellia Cipher in OpenPGP November 2007 been found to be vulnerable to attack. 5. IANA Considerations This document requires IANA to assign an algorithm number from the registry of OpenPGP Symmetric Key Algorithms that was created by [RFC4880]. 6. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3713] Matsui, M., Nakajima, J., and S. Moriai, "A Description of the Camellia Encryption Algorithm", RFC 3713, April 2004. [RFC4880] Callas, J., Donnerhacke, L., Finney, H., Shaw, D., and R. Thayer, "OpenPGP Message Format", RFC 4880, November 2007. Author's Address David Shaw Email: dshaw@jabberwocky.com Shaw Expires May 8, 2008 [Page 4] Internet-Draft The Camellia Cipher in OpenPGP November 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). 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. 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Information on the procedures with respect to rights in RFC 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. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Shaw Expires May 8, 2008 [Page 5]