W3C has announced the release of Canonical XML Version 1.0 as the first W3C Recommendation produced jointly by the W3C/IETF XML Signature Working Group. The Canonical XML specification "adds another critical piece to the Extensible Markup Language (XML) family of technologies under development at W3C, which began with the XML 1.0 Recommendation." The new specification "defines a method for serializing XML documents such that it eliminates incidental variances in their syntax as permitted by XML 1.0. This functionality is necessary to XML Signatures which requires documents to be consistently serialized for digital signature processing, so that these incidental variances do not invalidate the signature... Digital signatures provide integrity, signature assurance and non-repudiatability over Web data. Such features are especially important for documents that represent commitments such as contracts, price lists, and manifests. XML Signatures have the potential to provide reliable XML-based signature technology. However, various processors may introduce incidental changes into a document over the course of its processing. Canonical XML 1.0 provides a method of serializing an XML document into its canonical form. If two documents have the same canonical form, then the two documents are logically equivalent within the context of this specification. This relationship combined with XML Signature is critical for electronic commerce because it ensures the integrity of documents and protocol messages that travel between multiple XML processors." By publishing Canonical XML as a W3C Recommendation, the W3C consortium and its Director certify that the specification "is stable, contributes to Web interoperability, and has been reviewed by the W3C Membership, who are in favor of supporting its adoption by academic, industry, and research communities."
Abstract: "Any XML document is part of a set of XML documents that are logically equivalent within an application context, but which vary in physical representation based on syntactic changes permitted by XML 1.0 and Namespaces in XML. This specification describes a method for generating a physical representation, the canonical form, of an XML document that accounts for the permissible changes. Except for limitations regarding a few unusual cases, if two documents have the same canonical form, then the two documents are logically equivalent within the given application context. Note that two documents may have differing canonical forms yet still be equivalent in a given context based on application-specific equivalence rules for which no generalized XML specification could account."
- World Wide Web Consortium (W3C)
- Canonical XML Version 1.0
- Canonical XML interoperability report
- Announcement 2001-03-19: "World Wide Web Consortium Issues Canonical XML as a W3C Recommendation New XML specification provides foundation for digital signatures."
- W3C "Recommendation (REC)"
- W3C XML Signature Activity Statement
- IETF/W3C XML-Signature Working Group
- XML-Signature Syntax and Processing - Core Specification
- "XML Digital Signature (Signed XML - IETF/W3C)" - Main reference page.