International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Short-lived zero-knowledge proofs and signatures

Arasu Arun , New York University
Joseph Bonneau , New York University
Jeremy Clark , Concordia University
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Presentation: Slides
Conference: ASIACRYPT 2022
Abstract: We introduce the short-lived proof, a non-interactive proof of knowledge with a novel feature: after a specified period of time, the proof is no longer convincing. This time-delayed loss of soundness happens "naturally" without further involvement from the prover or any third party. We propose definitions for short-lived proofs as well as the special case of short-lived signatures. We show several practical constructions built using verifiable delay functions (VDFs). The key idea in our approach is to allow any party to forge any proof by executing a large sequential computation. Some constructions achieve a stronger property called reusable forgeability in which one sequential computation allows forging an arbitrary number of proofs of different statements. We also introduces two novel types of VDFs, re-randomizable VDFs and zero-knowledge VDFs, which may be of independent interest. Our constructions for short-lived Sigma-protocols and signatures are practically efficient for provers and verifiers, adding a few hundred bytes of overhead and tens to hundreds of milliseconds of proving/verification time.
Video from ASIACRYPT 2022
  title={Short-lived zero-knowledge proofs and signatures},
  author={Arasu Arun and Joseph Bonneau and Jeremy Clark},