Round-optimal Verifiable Oblivious Pseudorandom Functions From Ideal Lattices. / Albrecht, Martin; Davidson, Alex; Deo, Amit; Smart, Nigel P.

In: IACR Cryptology ePrint Archive, 01.11.2019.

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Abstract

Verifiable Oblivious Pseudorandom Functions (VOPRFs) are protocols that allow a client to learn verifiable pseudorandom function (PRF) evaluations on inputs of their choice. The PRF evaluations are computed by a server using their own secret key. The security of the protocol prevents both the server from learning anything about the client's input, and likewise the client from learning anything about the server's key. VOPRFs have many applications including password-based authentication, secret-sharing, anonymous authentication and efficient private set intersection. In this work, we construct the first round-optimal (online) VOPRF protocol that retains security from well-known lattice hardness assumptions. Our protocol requires constructions of non-interactive zero-knowledge arguments of knowledge (NIZKAoK). For analogues of Stern-type proofs in the lattice setting, we show that our VOPRF may be securely instantiated in the quantum random oracle model. We construct such arguments as extensions of prior work in the area of lattice-based zero-knowledge proof systems.
Original languageEnglish
JournalIACR Cryptology ePrint Archive
Publication statusE-pub ahead of print - 1 Nov 2019
This open access research output is licenced under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

ID: 36929207