Re: [webauthn] DPK attestation may create possible side channel attack on the batch key. (#1701)

on 23-Feb-2022 call: 
@agl: options 1 or 2 are ok.  
@ve7jtb maybe do option 2  and leave it to authnr to add a nonce if the signature alg being used is not properly side-channel resistant.
@agl: also authnr can select nonce length (?)  
@ve7jtb:  maybe make length max 32 bytes could be less?
@agl: if rp gets same sig, then ok, if not same, then need to do verify
@ve7jtb:  tho with non-det ecdsa,  will need to do verify each time even if nonce not included

@agl  current design: authnr stores dpk attstn sig and replays it (when there's no nonce).  adding nonce fine. RPs will need to validate sigs.




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Received on Wednesday, 23 February 2022 21:04:21 UTC