International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

A Distinguish attack on COSvd Ciphers

Authors:
Mohammad Ali Orumiehchi ha
Dr.R. Mirghadri
Download:
URL: http://eprint.iacr.org/2005/164
Search ePrint
Search Google
Abstract: Abstract: The COSvd Ciphers has been proposed by Filiol and others (2004). It is a strengthened version of COS stream cipher family denoted COSvd that has been adopted for at least one commercial standard. We propose a distinguish attack on this version, and prove that, it is distinguishable from a random stream. In the COSvd Cipher used one S-Box (10?8) on the final part of cipher. We focus on S-Box and use weakness this S-Box for distinguish attack. In addition, found a leak on HNLL that the sub s-boxes don?t select uniformly. We use this property for an Improve distinguish attack.
BibTeX
@misc{eprint-2005-12500,
  title={A Distinguish attack on COSvd Ciphers},
  booktitle={IACR Eprint archive},
  keywords={secret-key cryptography / Stream cipher, COSvd cipher, Distinguish attack, nonlinear feedback shift registers, chaotic layer.},
  url={http://eprint.iacr.org/2005/164},
  note={ maorum@yahoo.com 12919 received 16 May 2005},
  author={Mohammad Ali Orumiehchi ha and Dr.R. Mirghadri},
  year=2005
}