Non-malleable Time-Lock Puzzles and Applications

Cody Freitag, Ilan Komargodski, Rafael Pass, Naomi Sirkin*

*Corresponding author for this work

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

10 Scopus citations

Abstract

Time-lock puzzles are a mechanism for sending messages “to the future”, by allowing a sender to quickly generate a puzzle with an underlying message that remains hidden until a receiver spends a moderately large amount of time solving it. We introduce and construct a variant of a time-lock puzzle which is non-malleable, which roughly guarantees that it is impossible to “maul” a puzzle into one for a related message without solving it. Using non-malleable time-lock puzzles, we achieve the following applications: The first fair non-interactive multi-party protocols for coin flipping and auctions in the plain model without setup.Practically efficient fair multi-party protocols for coin flipping and auctions proven secure in the (auxiliary-input) random oracle model. As a key step towards proving the security of our protocols, we introduce the notion of functional non-malleability, which protects against tampering attacks that affect a specific function of the related messages. To support an unbounded number of participants in our protocols, our time-lock puzzles satisfy functional non-malleability in the fully concurrent setting. We additionally show that standard (non-functional) non-malleability is impossible to achieve in the concurrent setting (even in the random oracle model).

Original languageAmerican English
Title of host publicationTheory of Cryptography - 19th International Conference, TCC 2021, Proceedings
EditorsKobbi Nissim, Brent Waters, Brent Waters
PublisherSpringer Science and Business Media Deutschland GmbH
Pages447-479
Number of pages33
ISBN (Print)9783030904555
DOIs
StatePublished - 2021
Event19th International Conference on Theory of Cryptography, TCC 2021 - Raleigh, United States
Duration: 8 Nov 202111 Nov 2021

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume13044 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference19th International Conference on Theory of Cryptography, TCC 2021
Country/TerritoryUnited States
CityRaleigh
Period8/11/2111/11/21

Bibliographical note

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

Fingerprint

Dive into the research topics of 'Non-malleable Time-Lock Puzzles and Applications'. Together they form a unique fingerprint.

Cite this