Re: JSONWebSignature2020 vs JcsEd25519Signature2022

JsonWebSignature2020 should use URDNA2015.

The problem with using only JCS in a Data Integrity Proof is that it 
then only covers the document itself, not the underlying RDF dataset.
Changes in the @context would not result in a signature becoming invalid.

If people really want to do this, then it should be called something 
like JcsJsonWebSignature2023 to distinguish it from JsonWebSignature2020.
But I think the vc-jws (https://transmute-industries.github.io/vc-jws/) 
proposal would be preferable; however, with the same limitation that it 
only signs the document itself.

Markus

P.S.: I understand your argument about performance improvement, but I 
don't really understand why this would result in crypto agility gain.

On 1/25/23 19:10, Orie Steele wrote:
> Friends,
>
> I recently became aware of:
>
> https://codeberg.org/fediverse/fep/src/branch/main/feps/fep-c390.md
>
> The proposal suggests there may be a desire to use "Data Integrity 
> Proofs" with "Activity Streams"...
>
> This would be relevant to Mastodon and other fediverse projects.
>
> There has been past work in this area, here are some links:
>
> https://github.com/transmute-industries/RsaSignature2017/blob/master/src/__tests__/Mastodon.Integration.spec.js
>
> More recently these 2 items seem like they might potentially support 
> the request as it exists in fep-c390.
>
> https://github.com/w3c/vc-jws-2020
> https://github.com/decentralized-identity/JcsEd25519Signature2020
>
> There are 2 technical issues that have been discussed previously which 
> I would like to resurface in the context of this request:
>
> 1. Should JsonWebSignature2020 use URDNA2015 and JCS, or just JCS?... 
> (for those who don't know, URDNA uses JCS under the hood for `@json` 
> types).
> 2. Should JsonWebSignature2020 use `proofValue`... with detached JWS 
> just like it does today?
>
> It feels like we might have a nice performance improvement and crypto 
> agility gain, by having `JsonWebSignature2020` use JCS... but 
> otherwise align with the proposal from fep-390.
>
> Regards,
>
> OS
>
> -- 
> *ORIE STEELE*
> Chief Technical Officer
> www.transmute.industries
>
> <https://www.transmute.industries>