Improved Cryptanalysis of the Common Scrambling Algorithm Stream Cipher

Authors:
Leonie Simpson;Matt Henricksen;Wun-She Yap
Affiliations:
Information Security Institute, Queensland University of Technology, Brisbane, Australia Qld 4001;Institute for Infocomm Research, A*STAR, Singapore;Institute for Infocomm Research, A*STAR, Singapore
Venue:
ACISP '09 Proceedings of the 14th Australasian Conference on Information Security and Privacy
Year:
2009

Citing 2
Cited 1

Nondeterministic Algorithms

Journal of the ACM (JACM)
New applications of time memory data tradeoffs

ASIACRYPT'05 Proceedings of the 11th international conference on Theory and Application of Cryptology and Information Security

Breaking DVB-CSA

WEWoRC'11 Proceedings of the 4th Western European conference on Research in Cryptology

Quantified Score

Hi-index	0.00

Visualization

Abstract

This paper provides a fresh analysis of the widely-used Common Scrambling Algorithm stream cipher (CSA-SC). Firstly, a new representation of CSA-SC with a state size of only 89 bits is given, a significant reduction from the 103 bit state of a previous CSA-SC representation. Analysis of this 89-bit representation demonstrates that the basis of a previous guess-and-determine attack is flawed. Correcting this flaw increases the complexity of that attack so that it is worse than exhaustive key search. Although that attack is not feasible, the reduced state size of our representation makes it obvious that CSA-SC is vulnerable to several generic attacks, for which feasible parameters are given.