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(Commit-and-Prove) Predictable Arguments with Privacy

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  • Hamidreza Khoshakhlagh

Predictable arguments introduced by Faonio, Nielsen and Venturi [14] are private-coin argument systems where the answer of the prover can be predicted in advance by the verifier. In this work, we study predictable arguments with additional privacy properties. While the authors in [14] showed compilers for transforming PAs into PAs with zero-knowledge property, they left the construction of witness indistinguishable predictable arguments (WI-PA) in the plain model as an open problem. In this work, we first propose more efficient constructions of zero-knowledge predictable arguments (ZK-PA) based on trapdoor smooth projective hash functions (TSPHFs). Next, we consider the problem of WI-PA construction in the plain model and show how to transform PA into WI-PA using non-interactive witness-indistinguishable proofs. As a relaxation of predictable arguments, we additionally put forth a new notion of predictability called Commit-and-Prove Predictable Argument (CPPA), where except the first (reusable) message of the prover, all the prover’s responses can be predicted. We construct an efficient zero-knowledge CPPA in the non-programmable random oracle model for the class of all polynomial-size circuits. Finally, following the connection between predictable arguments and witness encryption, we show an application of CPPAs with privacy properties to the design of witness encryption schemes, where in addition to standard properties, we also require some level of privacy for the decryptors who own a valid witness for the statement used during the encryption process.

Original languageEnglish
Title of host publicationApplied Cryptography and Network Security : 20th International Conference, ACNS 2022, Proceedings
EditorsGiuseppe Ateniese, Daniele Venturi
Number of pages20
Publication yearJun 2022
ISBN (print)9783031092336
ISBN (Electronic)978-3-031-09234-3
Publication statusPublished - Jun 2022
Event20th International Conference on Applied Cryptography and Network Security, ACNS 2022 - Virtual, Online
Duration: 20 Jun 202223 Jun 2022


Conference20th International Conference on Applied Cryptography and Network Security, ACNS 2022
ByVirtual, Online
SeriesLecture Notes in Computer Science (LNCS)

Bibliographical note

Publisher Copyright:
© 2022, Springer Nature Switzerland AG.

    Research areas

  • Predictable arguments, Witness encryption, Witness indistinguishability, Zero-knowledge

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