XML signature

[Jordie Taitt]

I created an application that saves form data to XML. Now I am told that I will have to incorporate digital signatures into the resultant xml file as well, but I'm not sure how to go about it. Everything seems so abstract on the W3C website about the XML Signature specification.

Basically, I think I will have to ask the user a series of 7 'security' questions, and their answers will serve as the digital signature. Once I get the answers, I'm not sure what to do with it. I can't just put it into the xml file as plain text right? How do I make it fit the XML signature spec?

So can anyone point out to me exactly how to construct a digital signature and store it in an xml file?

I can't use any web services or anything like that either, as the application must not be connected to the internet.

[Balaji Loganathan]

Why do you want to ask 7 series of questions to ur user? ....

Digital signature is an electronic signature that applied over an eletronic content to prove that the content is not changed since it is signed.

Actually...W3C website has got lot of interesting link on this http://www.w3.org/Signature/ , check the source/code/toolkits section. To know what exactly in about xml digital signature , try to run the examples that come with apache xml security package or check this examples