Non-malleable Codes for Bounded Parallel-Time Tampering

Dana Dachman-Soled*, Ilan Komargodski, Rafael Pass

*Corresponding author for this work

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

6 Scopus citations


Non-malleable codes allow one to encode data in such a way that once a codeword is being tampered with, the modified codeword is either an encoding of the original message, or a completely unrelated one. Since the introduction of this notion by Dziembowski, Pietrzak, and Wichs (ICS ’10 and J. ACM ’18), there has been a large body of works realizing such coding schemes secure against various classes of tampering functions. It is well known that there is no efficient non-malleable code secure against all polynomial size tampering functions. Nevertheless, no code which is non-malleable for bounded polynomial size attackers is known and obtaining such a code has been a major open problem. We present the first construction of a non-malleable code secure against all polynomial size tampering functions that have bounded parallel time. This is an even larger class than all bounded polynomial size functions. In particular, this class includes all functions in non-uniform NC (and much more). Our construction is in the plain model (i.e., no trusted setup) and relies on several cryptographic assumptions such as keyless hash functions, time-lock puzzles, as well as other standard assumptions. Additionally, our construction has several appealing properties: the complexity of encoding is independent of the class of tampering functions and we can obtain (sub-)exponentially small error.

Original languageAmerican English
Title of host publicationAdvances in Cryptology – CRYPTO 2021 - 41st Annual International Cryptology Conference, CRYPTO 2021, Proceedings
EditorsTal Malkin, Chris Peikert
PublisherSpringer Science and Business Media Deutschland GmbH
Number of pages31
ISBN (Print)9783030842512
StatePublished - 2021
Event41st Annual International Cryptology Conference, CRYPTO 2021 - Virtual, Online
Duration: 16 Aug 202120 Aug 2021

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume12827 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference41st Annual International Cryptology Conference, CRYPTO 2021
CityVirtual, Online

Bibliographical note

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


Dive into the research topics of 'Non-malleable Codes for Bounded Parallel-Time Tampering'. Together they form a unique fingerprint.

Cite this