Garbled Circuits With Sublinear Evaluator

Abstract

Arecentlineofwork, Stacked Garbled Circuit(SGC), showed that Garbled Circuit (GC) can be improved for functions that include conditional behavior. SGC relieves the communication bottleneck of 2PC by only sending enough garbled material for a single branch out of the b total branches. Hence, communication is sublinear in the circuit size. However, both the evaluator and the generator pay in computation and perform at least factor $\log b$ extra work as compared to standard GC. We extend the sublinearity of SGC to also include the work performed by the GC evaluator E; thus we achieve a fully sublinear E, which is essential when optimizing for the online phase. We formalize our approach as a garbling scheme called GCWise: GC WIth Sublinear Evaluator. We show one attractive and immediate application, Garbled PIR, a primitive that marries GC with Private Information Retrieval. Garbled PIR allows the GC to non-interactively and sublinearly access a privately indexed element from a publicly known database, and then use this element in continued GC evaluation.

Available format(s)
Category
Cryptographic protocols
Publication info
Keywords
Garbled Circuits Stacked Garbling Private Information Retrieval
Contact author(s)
ahaque3 @ ncsu edu
heath davidanthony @ gatech edu
kolesnikov @ gatech edu
steve @ stealthsoftwareinc com
rafail @ cs ucla edu
akashshah08 @ ucla edu
History
2022-06-20: approved
See all versions
Short URL
https://ia.cr/2022/797

CC BY

BibTeX

@misc{cryptoeprint:2022/797,
author = {Abida Haque and David Heath and Vladimir Kolesnikov and Steve Lu and Rafail Ostrovsky and Akash Shah},
title = {Garbled Circuits With Sublinear Evaluator},
howpublished = {Cryptology ePrint Archive, Paper 2022/797},
year = {2022},
note = {\url{https://eprint.iacr.org/2022/797}},
url = {https://eprint.iacr.org/2022/797}
}

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