### Cryptanalysis of the FLIP Family of Stream Ciphers

Sébastien Duval, Virginie Lallemand, and Yann Rotella

##### Abstract

At Eurocrypt 2016, Méaux et al. proposed FLIP, a new family of stream ciphers intended for use in Fully Homomorphic Encryption systems. Unlike its competitors which either have a low initial noise that grows at each successive encryption, or a high constant noise, the FLIP family of ciphers achieves a low constant noise thanks to a new construction called filter permutator. In this paper, we present an attack on the early version of FLIP that exploits the structure of the filter function and the constant internal state of the cipher. Applying this attack to the two instantiations proposed by Méaux et al. allows for a key recovery in $2^{54}$ basic operations (resp. $2^{68}$), compared to the claimed security of $2^{80}$ (resp. $2^{128}$).

Available format(s)
Category
Secret-key cryptography
Publication info
Preprint. MINOR revision.
Keywords
Stream CipherGuess-and-determine attackFLIPFHE
Contact author(s)
virginie lallemand @ inria fr
History
Short URL
https://ia.cr/2016/271

CC BY

BibTeX

@misc{cryptoeprint:2016/271,
author = {Sébastien Duval and Virginie Lallemand and Yann Rotella},
title = {Cryptanalysis of the FLIP Family of Stream Ciphers},
howpublished = {Cryptology ePrint Archive, Paper 2016/271},
year = {2016},
note = {\url{https://eprint.iacr.org/2016/271}},
url = {https://eprint.iacr.org/2016/271}
}

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