BSEA-1 - A Stream Cipher Backdooring Technique
Abstract
Recent years have shown that more than ever governments and intelligence agencies try to control and bypass the cryptographic means used for the protection of data. Backdooring encryption algorithms is considered as the best way to enforce cryptographic control. Implementation backdoors (at the protocol/implementation/ma\-nagement level) are generally considered. In this paper we propose to address the most critical issue of backdoors: mathematical backdoors or by-design backdoors, which are put directly at the mathematical design of the encryption algorithm. Considering a particular family (among all the possible ones) of backdoors, we present BSEA-1, a stream cipher algorithm which contains a design backdoor enabling an effective cryptanalysis. The BSEA-1 algorithm uses a 120-bit key. The exploitation of the backdoor enables to break the cipher with around 2 Kbits of knowplaintext in a few seconds.
Cite
@article{arxiv.1903.11063,
title = {BSEA-1 - A Stream Cipher Backdooring Technique},
author = {Eric Filiol},
journal= {arXiv preprint arXiv:1903.11063},
year = {2019}
}
Comments
This work has been presented at the Ruscrypto 2019 conference in Moscow (March 21th, 2019). This paper concerns the continuation of our research work initiated in arXiv:1702.0647. As such, it takes up a reduced part of the abstract and introduction (section 1). All the other sections are totally different.