Extensible Markup Language Evidence Record Syntax (XMLERS)
RFC 6283

Internet Engineering Task Force (IETF)                  A. Jerman Blazic
Request for Comments: 6283                                     S. Saljic
Category: Standards Track                                         SETCCE
ISSN: 2070-1721                                               T. Gondrom
                                                               July 2011

       Extensible Markup Language Evidence Record Syntax (XMLERS)

Abstract

   In many scenarios, users must be able to demonstrate the (time of)
   existence, integrity, and validity of data including signed data for
   long or undetermined periods of time.  This document specifies XML
   syntax and processing rules for creating evidence for long-term non-
   repudiation of existence and integrity of data.  The Extensible
   Markup Language Evidence Record Syntax XMLERS provides alternative
   syntax and processing rules to the ASN.1 (Abstract Syntax Notation
   One) ERS (Evidence Record Syntax) (RFC 4998) syntax by using XML.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6283.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Blazic, et al.               Standards Track                    [Page 1]
RFC 6283                         XMLERS                        July 2011

Table of Contents

   1. Introduction ....................................................3
      1.1. Motivation .................................................3
      1.2. General Overview and Requirements ..........................4
      1.3. Terminology ................................................6
      1.4. Conventions Used in This Document ..........................7
   2. Evidence Record .................................................7
      2.1. Structure ..................................................8
      2.2. Generation ................................................12
      2.3. Verification ..............................................13
   3. Archive Time-Stamp .............................................13
      3.1. Structure .................................................13
           3.1.1. Hash Tree ..........................................13
           3.1.2. Time-Stamp .........................................14
           3.1.3. Cryptographic Information List .....................15
      3.2. Generation ................................................16
           3.2.1. Generation of Hash Tree ............................17
           3.2.2. Reduction of Hash Tree .............................19
      3.3. Verification ..............................................21
   4. Archive Time-Stamp Sequence and Archive Time-Stamp Chain .......22
      4.1. Structure .................................................23
           4.1.1. Digest Method ......................................23
           4.1.2. Canonicalization Method ............................24
      4.2. Generation ................................................25
           4.2.1. Time-Stamp Renewal .................................25
           4.2.2. Hash Tree Renewal ..................................26
      4.3. Verification ..............................................27
   5. Encryption .....................................................28
   6. Version ........................................................29
   7. Storage of Policies ............................................30
   8. XSD Schema for the Evidence Record .............................30
   9. Security Considerations ........................................34
      9.1. Secure Algorithms .........................................34
      9.2. Redundancy ................................................34