[CFRG] Oblivious issuance of proofs
Michele Orrù <lists@tumbolandia.net> Fri, 19 April 2024 11:37 UTC
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From: Michele Orrù <lists@tumbolandia.net>
Date: Fri, 19 Apr 2024 13:37:00 +0200
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Subject: [CFRG] Oblivious issuance of proofs
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Hello, I wanted to bring to the attention of the CFRG, and in particular the Privacy Pass working group, to a recent work of Stefano Tessaro, Greg Zaverucha, Chenzi Zhu, and myself, ePrint 2023/1635 < https://eprint.iacr.org/2023/1635>. The paper describes how to generalize how to issue proofs (in particular Schnorr proofs) in such a way that the proof cannot be linked back to the interaction that produced it. The resulting proof is transferable and can be verified non-interactively by anyone. As an example, we show that it's possible to issue the DLEQ proof in Privacy Pass "obliviously" and effectively make the VOPRF Privacy Pass publicly verifiable at a minimal change to the current infrastructure. This may be an alternative to blind RSA for publicly-verifiable anonymous tokens. More in general, we see oblivious proofs as extension of blind signatures, but for more complex statements than "knowledge of a signing key". We are happy to answer any questions, gather thoughts and feedback on this primitive! Best, – Michele.
- [CFRG] Oblivious issuance of proofs Michele Orrù