### Correcting Subverted Random Oracles

Alexander Russell, Qiang Tang, Moti Yung, Hong-Sheng Zhou, and Jiadong Zhu

##### Abstract

The random oracle methodology has proven to be a powerful tool for designing and reasoning about cryptographic schemes. In this paper, we focus on the basic problem of correcting faulty—or adversarially corrupted—random oracles, so that they can be confidently applied for such cryptographic purposes. We prove that a simple construction can transform a “subverted” random oracle—which disagrees with the original one at a small fraction of inputs—into an object that is indifferentiable from a random function, even if the adversary is made aware of all randomness used in the transformation. Our results permit future designers of cryptographic primitives in typical kleptographic settings (i.e., those permitting adversaries that subvert or replace basic cryptographic algorithms) to use random oracles as a trusted black box.

Available format(s)
Category
Foundations
Publication info
A major revision of an IACR publication in CRYPTO 2018
DOI
10.1007/978-3-319-96881-0_9
Keywords
kleptographycliptographyrandom oraclesindifferenttiability
Contact author(s)
qtang84 @ gmail com
History
Short URL
https://ia.cr/2021/042

CC BY

BibTeX

@misc{cryptoeprint:2021/042,
author = {Alexander Russell and Qiang Tang and Moti Yung and Hong-Sheng Zhou and Jiadong Zhu},
title = {Correcting Subverted Random Oracles},
howpublished = {Cryptology ePrint Archive, Paper 2021/042},
year = {2021},
doi = {10.1007/978-3-319-96881-0_9},
note = {\url{https://eprint.iacr.org/2021/042}},
url = {https://eprint.iacr.org/2021/042}
}

Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.