From XML.com: "The very features that make XML so powerful for business transactions (e.g., semantically rich and structured data, text-based, and
Web-ready nature) provide both challenges and opportunities for the application of encryption and digital signature operations to
XML-encoded data. For example, in many workflow scenarios where an XML document flows stepwise between participants, and
where a digital signature implies some sort of commitment or assertion, each participant may wish to sign only that portion for which
they are responsible and assume a concomitant level of liability. Older standards for digital signatures provide neither syntax for
capturing this sort of high-granularity signature nor mechanisms for expressing which portion a principal wishes to sign."
August 10, 2001