Both XML Signature and XML Encryption use XML Canonicalization standards to produce canonical form of the original XML document. 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. Implementation of both these standards were included in libxml2 library because these algorithms could be interested for other applications as well.

• Canonical XML 1.0 (included in libxml2)
• Exclusive Canonical XML 1.0 (included in libxml2)
• Canonical XML 1.1 (included in libxml2)