Hi!

Did you make any progress on that front since 2020? I'm interested in the topic too. But I would be more interested in doing the opposite actually, in particular including the signature into the attestation of the timestamp. I wonder also if we could use that signature as a commitment operation.

My end goal would be to have the signature and the attestation in one unique file, that would follow the same standard for everyone, so that we would only need that file, the public key of the signature and the original file to verify what I call the authenticity of the file. Authenticity being for me a combination of proof of date provided by timestamp + proof of provenance provided by signature.

In the case where we would use PGP for the signature for instance I believe we could build nice-easy-to-use verifiers for end-users, since we have very cool way of retrieving public keys.

At this stage of my research, I wonder if creating timestamps attestations that would include signature is something that I could do anyway (is it possible to use other things than sha256 for commitment operations) and if I could invente my own standard to do so, or if there is something that exists that I could use.

Alternatively, the solution to my problem is simply to timestamp signatures. But this is less nice because my ultimate dream would be also to have traceability on one file by using successive signatures and timestamp. But if each signature is timestamped separately, only if I have all the signatures I can have the latest status. Whereas in my dream scenario I would simply have to upgrade the timestamp attestation to get the latest signature of my file. This would be the ultimate traceability tool for files.