Digital Certificate for digitally signing a xml document

Question

I have 3rd party integration requirement that xml docs be digitally signed with the following parameters: Signature keys shall be 256bit Elliptic Curve Keys, have a length of 256 bits, use the NIST SuiteB P-256 curve. Do I need to to have a digital certificate to digitally sign a xml document, to meet the these (above) requirements. or do the libraries for java or c# provide the capability to digitally sign while meeting these requirements.

Answer 1

Yes, you need a digital certificate. That does not mean you need to buy one. You could generate one yourself.