Leveraging Linear Decryption: Rate-1 Fully-Homomorphic Encryption and Time-Lock Puzzles

Zvika Brakerski, Nico Döttling, Sanjam Garg, Giulio Malavolta

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

Abstract

We show how to combine a fully-homomorphic encryption scheme with linear decryption and a linearly-homomorphic encryption schemes to obtain constructions with new properties. Specifically, we present the following new results. (1)Rate-1 Fully-Homomorphic Encryption: We construct the first scheme with message-to-ciphertext length ratio (i.e., rate) (formula presented). Our scheme is based on the hardness of the Learning with Errors (LWE) problem and(formula presented) is proportional to the noise-to-modulus ratio of the assumption. Our building block is a construction of a new high-rate linearly-homomorphic encryption.One application of this result is the first general-purpose secure function evaluation protocol in the preprocessing model where the communication complexity is within additive factor of the optimal insecure protocol.(2)Fully-Homomorphic Time-Lock Puzzles: We construct the first time-lock puzzle where one can evaluate any function over a set of puzzles without solving them, from standard assumptions. Prior work required the existence of sub-exponentially hard indistinguishability obfuscation.

Original languageEnglish
Title of host publicationTheory of Cryptography - 17th International Conference, TCC 2019, Proceedings
EditorsDennis Hofheinz, Alon Rosen
PublisherSpringer Verlag
Pages407-437
Number of pages31
ISBN (Electronic)978-3-030-36033-7
ISBN (Print)9783030360320
DOIs
StatePublished - 2019
Event17th International Conference on Theory of Cryptography, TCC 2019 - Nuremberg, Germany
Duration: 1 Dec 20195 Dec 2019

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume11892 LNCS

Conference

Conference17th International Conference on Theory of Cryptography, TCC 2019
Country/TerritoryGermany
CityNuremberg
Period1/12/195/12/19

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • General Computer Science

Fingerprint

Dive into the research topics of 'Leveraging Linear Decryption: Rate-1 Fully-Homomorphic Encryption and Time-Lock Puzzles'. Together they form a unique fingerprint.

Cite this