pop.json shall produce a verifiable presentation and not a verifiable credential.

[francis-pouatcha]

Reviewing the concept of a server A server can certify a self generate document with a pop.json the way we generate it actually. But this is not a verifiable credential, but rather a verifiable presentation.

• Repeated calls must return new signature, even if sent with the same challenge.
• We can use the nonce parameter to always include a nonce in the proof

[francis-pouatcha]

The document actually produce is already a verifiable presentation. We just need to change the document type.