if e token itself creates message digest, or service provider of digital signature gives some software to create it. I am a little bit confused.kindly help.

Dear Sir,
Etoken is not creating message digest value it’s the singing software used for the evelope /enveloping/ detached signature which need to play key role in generating and calculating the digest valuve & saving it to some repository to cross verify the signed doc by matching the digest value .Token plays important role in storing the digital identity i.e certificate