Need to create Digital Signature & Encrypt the File

Hi Experts,

I have an requirement, I need to create a module in which I need to pass four values (Namely signing key, signing algorithm, encyption key and encryption algorithm) through parameters as inputs. Based on these parameters, I need to create the signature for the input xml file and I have to encrypted the file. Please Guide me. Give some useful links, documents or codes to how to do this. Help me in this regard.

Thanks in Advance,

Venkatesh.K