Towards Accountability in CRS Generation

Prabhanjan Ananth, Gilad Asharov, Hila Dahari, Vipul Goyal

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

It is well known that several cryptographic primitives cannot be achieved without a common reference string (CRS). Those include, for instance, non-interactive zero-knowledge for NP, or maliciously secure computation in fewer than four rounds. The security of those primitives heavily relies upon on the assumption that the trusted authority, who generates the CRS, does not misuse the randomness used in the CRS generation. However, we argue that there is no such thing as an unconditionally trusted authority and every authority must be held accountable for any trust to be well-founded. Indeed, a malicious authority can, for instance, recover private inputs of honest parties given transcripts of the protocols executed with respect to the CRS it has generated. While eliminating trust in the trusted authority may not be entirely feasible, can we at least move towards achieving some notion of accountability? We propose a new notion in which, if the CRS authority releases the private inputs of protocol executions to others, we can then provide a publicly-verifiable proof that certifies that the authority misbehaved. We study the feasibility of this notion in the context of non-interactive zero knowledge and two-round secure two-party computation.

Original languageEnglish
Title of host publicationAdvances in Cryptology – EUROCRYPT 2021 - 40th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Proceedings
EditorsAnne Canteaut, François-Xavier Standaert
PublisherSpringer Science and Business Media Deutschland GmbH
Pages278-308
Number of pages31
ISBN (Print)9783030778828
DOIs
StatePublished - 2021
Event40th Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2021 - Zagreb, Croatia
Duration: 17 Oct 202121 Oct 2021

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume12698 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference40th Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2021
Country/TerritoryCroatia
CityZagreb
Period17/10/2121/10/21

Bibliographical note

Publisher Copyright:
© 2021, International Association for Cryptologic Research.

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