Re: [Agenda] W3C CCG 2024-05-07 - Parallel Signatures in Verifiable Credentials

Hi all, I wrote up the explanatory section 
https://w3c.github.io/vc-data-integrity/#understanding-proof-sets-and-proof-chains 
to help distinguish the two concepts of proof sets and chains. For a 
more elaborate /proof chain/ example than a notary, I used a business 
approval procedure moving up the “chain of command”, for a /proof set/ I 
used the example of a different individuals digitally signing a 
electronic birthday card.

When the term “parallel signatures” is used I’ve taken it to mean that 
we are furnishing multiple proofs that utilize different cryptographic 
suites (EdDSA, ECDSA, ECDSA-SD, BBS), though we have never formally 
defined the term.

Cheers Greg B.

------------------------------------------------------------------------

Dr. Greg M. Bernstein, https://www.grotto-networking.com


On 5/13/2024 7:25 AM, John, Anil wrote:

> >could prove problematic if parallel proofs represent different 
> individuals/issuers who signed the same document …
>
> I have an aversion to the using the “parallel signature” term because, 
> to me, it conflates two different things:
>
> Proof Set
>
> https://www.w3.org/TR/vc-data-integrity/#proof-sets

>
> Proof Chain
>
> https://www.w3.org/TR/vc-data-integrity/#proof-chains

>
> I tend to describe a “proof set” as something that enables a single 
> issuer to digitally sign the same credential using different signature 
> types, while a “proof chain” supports capabilities such as multiple 
> entities signing the same document in a particular order, as needed 
> for a notarization use case or for a workflow approval use case.  I’ve 
> also thought that the proof chain use cases do not appear to be a good 
> fit when combined with selective disclosure needs.
>
> Best Regards,
>
> Anil
>
> Anil John
>
> Technical Director, Silicon Valley Innovation Program
>
> Science and Technology Directorate
>
> US Department of Homeland Security
>
> Washington, DC, USA
>
> Schedule a meeting with me (30 minutes; non-DHS people only) 
> <https://outlook.office.com/bookwithme/user/6250c4b6cae94d549b6db87b72b0b6d5@hq.dhs.gov?anonymous&ep=plink>
>
> Time Zone: UTC-05:00 (US Eastern Time)
>
> Email Response Time – 24 Hours or more; I sometimes send emails 
> outside of business days/times because it works for me; please do not 
> feel any obligation to reply to them outside of your normal working 
> patterns.
>
> A picture containing graphical user interface Description 
> automatically generated 
> <https://www.dhs.gov/science-and-technology>/Users/holly.johnson/Library/Containers/com.microsoft.Outlook/Data/Library/Caches/Signatures/signature_1972159395
>
> This document contains pre-decisional and/or deliberative process 
> information exempt from mandatory disclosure under the Freedom of 
> Information Act, 5 U.S.C. 552(b)(5). Do not release without prior 
> approval of the Department of Homeland Security.
>
​