Re: [PROPOSED WORK ITEM] W3C-VC-QP - Verifiable Credential Quantum Proof #247

This statement:
> Currently no QP signature offers zero-knowledge proof or unlinkability
features, so part of the task of the WG might involve combining QP
signatures with more privacy-enhancing signining algorithms (such as BBS or
ECDSA-SD).

Is somewhat concerning - combinations / hybrid schemes are non-trivial and
I would personally recommend following CFRG, and also SAAG / PQUIP (and
also JOSE / COSE) for challenges that are arising in that area and avoid
defining any hybrids in a group that does not have the expertise to review
the side effects of that combination. Also, bear in mind that from a review
standpoint, more focus is being put on review of KEMs and providing
protection around store now, decrypt later attacks in relation to hybrids
than on the signature side (since you can sign multiple times with
different algorithms).

If you mean multiple signatures - e.g. one BBS+ for selective disclosure,
etc, and one for post quantum support then i think that is ok to note.

Mike Prorock
Founder
https://mesur.io/



On Wed, Mar 27, 2024 at 12:41 PM Andrea D'Intino <andrea@dyne.org> wrote:

> Hi everyone,
>
> we are seeking feedback on a new CCG Work Item proposal regarding the
> quantum-prooof signatures for Verifiable Credentials across devices and
> websites. Please leave your support or concerns here:
>
> https://github.com/w3c-ccg/community/issues/247
>
> # New Work Item Proposal
>
> The proposal is about defining a new specification to define the
> associated Data Integrity cryptosuite that can be used to construct digital
> signatures and proofs using quantum-proof (QP) signing algorithms, starting
> with [Dilithium](https://pq-crystals.org/dilithium/index.shtml).
>
> The notable feature of this family of signature schemes is the
> quantum-resistance, according to the [NIST competition results](
> https://csrc.nist.gov/Projects/post-quantum-cryptography/selected-algorithms-2022).
>
>
> Currently no QP signature offers zero-knowledge proof or unlinkability
> features, so part of the task of the WG might involve combining QP
> signatures with more privacy-enhancing signining algorithms (such as BBS or
> ECDSA-SD).
>
> We aim to initially focus on Dilithium2 (as apparently there is the only
> signature scheme readily available) and progressively extend the specs to
> accomodate more signature schemes.
>
>
> ## Include Link to Abstract or Draft
>
> https://msporny.github.io/di-quantum-safe/#abstract
>
> * Dilithium signature implementations (C language): [pq-crystals](
> https://github.com/pq-crystals/dilithium.git), [pq-clean](
> https://github.com/PQClean/PQClean)
> * Zenroom implementation of the [Dilithium signatures](
> https://dev.zenroom.org/#/pages/zencode-scenarios-qp?id=dilithium)
> * Specification of _did:dyne_ W3C-DID method supporting [Dilithium pubkey](
> https://dyne.org/W3C-DID/#dilithium2verificationkey)
> * Curl POST to test W3C-VC-QP signing [API](https://pastebin.com/h1vWd8eP)
> * Preliminary W3C-VC-QP proof structure:
>
> ```
> "proof": {
>       "created":
> "1710861739438",                                           //epoch
>       "cryptosuite":
> "experimental-dilithium2-2024",                         //proposed
> cryptosuite name
>       "id":
> "H+4899Oefjch3wmRTfczR08jSNdJ+Jr67kadQO7/7uc=",                 //hash of
> the W3C-VC
>       "proofPurpose": "assertionMethod",
>       "proofValue": "...Dilithium2signature...",
>       "type": "DataIntegrityProof",
>       "verificationMethod": "did:dyne:..#dilithium_public_key"
> // Dilithium2 pubkey of the issuer
>     }
>
> ```
>
> ## List Owners
>
> > Identify 1 lead (person responsible for advancing the work item) and at
> least 1 other owner. Ideally, include their github usernames
>
> @andrea-dintino @msporny, @jaromil, @wip-abramson
>
> ## Work Item Questions
>
> 1. Explain what you are trying to do using no jargon or acronyms.
>
> Draft a standard for a W3C-VC proof format, that supports Dilithium (and
> potentially further QP algorithms) signatures
>
> 2. How is it done today, and what are the limits of the current practice?
>
> First experiment of Dilithium signed W3C-VC formats.
>
> 4. What is new in your approach and why do you think it will be successful?
>
> Building on top of extending w3C-VC cryptosuite standards, aiming to be as
> little invasive and disruptive as possible.
>
> 5. How are you involving participants from multiple skill sets and global
> locations in this work item? (Skill sets: technical, design, product,
> marketing, anthropological, and UX. Global locations: the Americas, APAC,
> Europe, Middle East.)
>
> Initial participant group includes cryptographers and developers from
> Dyne.org (Netherlands), DigitalBazaar (US) and Will Abramson (US)
>
> 6. What actions are you taking to make this work item accessible to a
> non-technical audience?
>
> While the topic is deeply technical, the specification should attempt to
> provide a gentle introduction to the topic via a non-technical introduction
> as well as non-technical use cases with imagery that is accessible to the
> general population.
>
>
> Cheers,
>
> | Andrea D'Intino | +45  21 62 79 18 | Project Manager
> | https://Dyne.org think &do tank  | software to empower communities
> | ⚷ crypto κρυπτο крипто गुप्त् 加密הצפנה المشفره
>
>