XML-Signature XPath Filter 2.0

XML Signature [XML-DSig] recommends
a standard means for specifying information content to be digitally
signed and for representing the resulting digital signatures in
XML. Some applications require the ability to specify a subset of a
given XML document as the information content to be signed. The XML
Signature specification meets this requirement with the XPath
transform. However, this transform can be difficult to implement
efficiently with existing technologies. This specification defines
a new XML Signature transform to facilitate the development of
efficient document subsetting implementations that interoperate
under similar performance profiles.