Actually, no, not really, XML people have THEIR OWN methods of dealing with that, so signing with GPG while well-tested and working well, would be considered non-standard and you can encounter problems with interoperability.

Actually both Yes and No depending on how you define an XML document. If you are referring to solely the content, then this is where http://www.w3.org/Signature comes in... the digital signature is stored outside of the document somewhere

however, if you are referring to the document as including both the content AND the xml tokens, then you will be writing the digital signature for the file itself. the digital signature is stored outside of the document somewhere

Now, http://www.w3.org/Signature also covers an encapsulated xml document where the you have a ** DOCUMENT ** within a top level document but the digital signature only covers the encapsulated xml document. The digital signature is stored within the top level document.

Here is a quick write up on XML Digital Signatures

Jason L. Froebe

No one has seen what you have seen, and until that happens, we're all going to think that you're nuts. - Jack O'Neil, Stargate SG-1