RE: Breakthrough: Parallel Signatures - NIST, ECDSA-SD, and BBS

>We now have the first public technical demonstration of cryptographic layering[1] (aka parallel signatures) on a Verifiable Credential that

>uses government approved cryptographic algorithms (FIPS-140) for full and selective disclosure of a VC, as well

>as unlinkable signatures using BBS, to achieve advanced privacy protections.

>What this means is that a single Verifiable Credential can be issued that meets all government requirements when it comes to cryptographic

>algorithms as well as one that addresses privacy concerns highlighted by civil society and existing government privacy regulations.



This is excellent to finally see this working in practice! Congratulations!



I am particularly interested to note that this implementation can also be used to demonstrate what is actually meant by unlinkable digital signatures:

  *   Issue a ECDSA-SD protected credential and present to a Verifier asking for ‘Country Only’ multiple times (and see that the signature remains the same)
  *   Issue a BBS protected credential and present it to a Verifier asking for ‘Country Only’ multiple times (and see that the signatures do NOT remain the same)



Manu – Three questions:



  1.  Does this approach allow for the support of quantum safe signature schemes as another option down the line when those become more specified?
  2.  Does this approach allow for the support of anoncred based signatures in parallel with others?
  3.  It sounds like the wallet has a specific role here >> “I'll pick the one that the Verifier will accept and that maximizes privacy for the Holder: BBS”; which also implies that the wallet could choose to be NOT select the most privacy preserving option << which then follows that this is an area that people who are making choices between wallets need to be aware and be educated on what the wallet could do behind the scenes. Is my understanding correct here?


Best Regards,

Anil

Anil John
Technical Director, Silicon Valley Innovation Program
Science and Technology Directorate
US Department of Homeland Security
Washington, DC, USA

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