Cryptology ePrint Archive: Report 2001/080

COS Ciphers are not "extremely weak"! - The Design Rationale of COS Ciphers

Eric Filiol and Caroline Fontaine

Abstract: This note summarizes the results of Babbage's cryptanalysis of COS ciphers and shows that in fact COS ciphers are not weak as claimed. These ciphers have been designed according a novel concept of encryption directly determined by the context of use. This concept is here more precisely defined.

Category / Keywords: secret-key cryptography / stream cipher,cryptanalysis, COS, Non Linear Feedback Shift Registers, copyright protection

Date: received 17 Sep 2001

Contact author: Eric Filiol at inria fr

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | BibTeX Citation

Version: 20010917:171103 (All versions of this report)

Short URL: ia.cr/2001/080