Digitally signed documents/Strong Encryption: Python modules ??

[Thomas Weholt]

Hi,

I want to create digitally signed documents using Python and some standard
protocoll or technology.
More specific; I got a xml-document, I want to create a signature so that
people can verify that the document isn't tampered with. Legal issues, ie.
making digitally signed documents/files, legally binding, are also very
interesting.

Generating a SHA checksum seems a little "light". What are my choices?

I want to use common protocols ( stuff like PGP and/or standards available
to/in other applications and programming languages ) and are also looking
for info on strong encryption used in relation to digitally signed
documents.

What are the best way to do this? Any comments or hints are very welcome.

Best regards,
Thomas Weholt