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cryptimeleon / craco

CRyptogrAphic COnstructions
Apache License 2.0
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SPoK missing in bbs signature scheme #108

Open ifteheralom opened 8 months ago

ifteheralom commented 8 months ago

BBS signature scheme is missing proof of knowledge. It's a vital part of the BBS scheme for it adds selective disclosure feature. Can the current implementation be extended for SPoK?

JanBobolz commented 8 months ago

Hi,

certainly! It should be relatively easy to do using the Schnorr framework. We have a similar "proof that I know a signature" example for Pointcheval Sanders signatures in the Subzero example list, too, so you can generate a first version of the proof you need using Subzero.

I'm quite busy right now, so I won't implement this myself (though it would be a nice addition). But if you want to give it a shot and you run into questions or weird issues, don't hesitate to contact me :)