Validation and long term T. Gondrom verification data for Evidence Open Text Corporation Records and signed documents October 16, 2006 Internet-Draft Intended status: Informational Expires: April 19, 2007 Verification Data draft-ietf-ltans-validate-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 April 19, 2007. Copyright Notice Copyright (C) The Internet Society (2006). Abstract Digitally signed documents and data in a LTANS service receive the signature renwal procedures and non-repudiation services. As documents can be stored for very long (theoretically inifinite) times, it is very important to understand which data is and will be necessary for the verification of the contained digital signatures and the applied timestamps and the evidence records. This document Gondrom Expires April 19, 2007 [Page 1] Internet-Draft Verification Data October 2006 shall describe various pieces of information which SHOULD and MUST be provided to effectively verify evidence records and their protected data and signatures. Conventions used in this document 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]. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Verification data for Evidence Records . . . . . . . . . . . . 3 3. Verification data for docuemnts secured by the Evidence Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 5. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4 5.1. Normative References . . . . . . . . . . . . . . . . . . . 4 5.2. Informative References . . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 5 Intellectual Property and Copyright Statements . . . . . . . . . . 6 Gondrom Expires April 19, 2007 [Page 2] Internet-Draft Verification Data October 2006 1. Introduction Data and documents stored in Long term archiving services may contain digitally signed or encrypted data and their integrity may be assured with the used of timestamps and archivetimestamps as sepcified in ERS. As such data and it's proof of existance and non-repudiation may be verified at a point in time very far in the future, it is very important to analyse and understand what information may be needed for this verification and what controls need to be implemented to ensure the avaliability and integrity of this data. 2. Verification data for Evidence Records Evidence Records contain hashtrrees secured with time stamps. The security and verification of the hhashtrees basically only depends on the used hash algorithm and its possible parameters. In general no external verification data like CRLs are necessary. The time stamps used in the Evidence Record are based on digital signatures and for this need besides the information about the used algorithms also additional verification data like Certificate Revolcation Lists (CRLs), OCSP responses and certificates of all parties involved in the issuance of the time stamp certificate. To correctly verify the time stamps in the Evidence Record an expert needs in every case to verify that the used private key has not been compromised before it has been used. Which means the verifier needs a OCSP resonse or a CRL to verify that the cused certificate has not been revocated. Additionally to fully evauluate the correct chain of issuers all cetrificates up to the root need to be checked. In cases where an specailly accredited authority has issued the trusted time stamp authority, it could be assumed that the compromise of the used keys would have so much impact that it would be publicly known even without directly checking the CRL or OCSP status of the used certificate. This situation can justify that it is only necessary to store all certificates but no CRL or OCSP response with the time stamp used in teh Evdience Record. 3. Verification data for docuemnts secured by the Evidence Records All verification data for the documents stored in the system needs to be protected and stored in a non-repudiation system for the whole time where a later verification is needed. Gondrom Expires April 19, 2007 [Page 3] Internet-Draft Verification Data October 2006 This explecitaly includes OCSP or CRL data and all certificates (including the complete chains for the used signatures. 4. Security Considerations Long term availability and integrity of verification data The verification data has to be stored and available including non- repudiation for all verification data. 5. References 5.1. Normative References [ANSX995] American National Standard for Financial Services, "Trusted Timestamp Management and Security", ANSX X9.95- 2005, June 2005. [I180141] ISO/IEC JTC 1/SC 27, "Time stamping services - Part 1: Framework", ISO ISO-18014-1, February 2002. [I180142] ISO/IEC JTC 1/SC 27, "Time stamping services - Part 2: Mechanisms producing independent tokens", ISO ISO-18014-2, December 2002. [I180143] ISO/IEC JTC 1/SC 27, "Time stamping services - Part 3: Mechanisms producing linked tokens", ISO ISO-18014-3, February 2004. [RFC2026] Bradner, S., "The Internet Standards Process -- Revision 3", RFC 2026, 1996. [RFC2119] Bradner, S., "Key Words for Use in RFCs to Indicate Requirement Levels", RFC 2119, 1997. [RFC3126] Adams, C., Pinkas, D., Ross, J., and N. Pope, "Electronic Signature Formats for long term electronic signatures", RFC 3126, 2001. [RFC3161] Adams, C., Cain, P., Pinkas, D., and R. Zuccherato, "Internet X.509 Public Key Infrastructure Time-Stamp Protocol (TSP)", RFC 3161, August 2001. [RFC3280] Housley, R., Polk, W., Ford, W., and D. Solo, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 3280, Gondrom Expires April 19, 2007 [Page 4] Internet-Draft Verification Data October 2006 August 2001. [RFC3852] Housley, R., "Cryptographic Message Syntax (CMS)", RFC 3852, July 2004. 5.2. Informative References [ETSI2003] European Telecommunication Standards Institute (ETSI), Electronic Signatures and Infrastructures (ESI);, "Algorithms and Parameters for Secure Electronic Signatures", ETSI SR 002 176 V1.1.1, March 2003. [MER1980] Merkle, R., "Protocols for Public Key Cryptosystems, Proceedings of the 1980 IEEE Symposium on Security and Privacy (Oakland, CA, USA)", pages 122-134, April 1980. [REQ2004] Wallace, C., Brandner, R., and U. Pordesch, "Long-term Archive Service Requirements", I-D ???, 2005. Author's Address Tobias Gondrom Open Text Corporation Werner-von-Siemens-Ring 20 Grasbrunn, Munich D-85630 Germany Phone: +49 (0) 89 4629-1816 Fax: +49 (0) 89 4629-33-1816 Email: tobias.gondrom@opentext.com Gondrom Expires April 19, 2007 [Page 5] Internet-Draft Verification Data October 2006 Full Copyright Statement Copyright (C) The Internet Society (2006). 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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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). Gondrom Expires April 19, 2007 [Page 6]