Composition with Knowledge Assumptions

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Zero-knowledge succinct non-interactive arguments (zk-SNARKs) rely on knowledge assumptions for their security. Meanwhile, as the complexity and scale of cryptographic systems continues to grow, the composition of secure protocols is of vital importance. The current gold standards of composable security, the Universal Composability and Constructive Cryptography frameworks cannot capture knowledge assumptions, as their core proofs of composition prohibit white-box extraction. In this paper, we present a formal model allowing the composition of knowledge assumptions. Despite showing impossibility for the general case, we demonstrate the model’s usefulness when limiting knowledge assumptions to few instances of protocols at a time. We finish by providing the first instance of a simultaneously succinct and composable zk-SNARK, by using existing results within our framework.
Original languageEnglish
Title of host publicationAdvances in Cryptology – CRYPTO 2021
EditorsTal Malkin, Chris Peikert
PublisherSpringer, Cham
Number of pages30
ISBN (Electronic)978-3-030-84259-8
ISBN (Print)978-3-030-84258-1
Publication statusPublished - 11 Aug 2021
EventCrypto 2021 - Online
Duration: 16 Aug 202120 Aug 2021

Publication series

NameLecture Notes in Computer Science
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


ConferenceCrypto 2021
Internet address


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