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Analysis of the Bit-Search Generator and Sequence Compression Techniques

  • Aline Gouget
  • Hervé Sibert
  • Côme Berbain
  • Nicolas Courtois
  • Blandine Debraize
  • Chris Mitchell
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3557)

Abstract

Algebraic attacks on stream ciphers apply (at least theoretically) to all LFSR-based stream ciphers that are clocked in a simple and/or easily predictable way. One interesting approach to help resist such attacks is to add a component that de-synchronizes the output bits of the cipher from the clock of the LFSR. The Bit-search generator, recently proposed by Gouget and Sibert, is inspired by the so-called Self-Shrinking Generator which is known for its simplicity (conception and implementation-wise) linked with some interesting properties. In this paper, we introduce two modified versions of the BSG, called MBSG and ABSG, and some of their properties are studied. We apply a range of cryptanalytic techniques in order to compare the security of the BSGs.

Keywords

Input Sequence Linear Complexity Information Rate Stream Cipher Output Sequence 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 1.
    Armknecht, F., Krause, M.: Algebraic attacks on combiners with memory. In: Boneh, D. (ed.) CRYPTO 2003. LNCS, vol. 2729, pp. 162–176. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  2. 2.
    Coppersmith, D., Krawczyk, H., Mansour, Y.: The shrinking generator. In: Stinson, D.R. (ed.) CRYPTO 1993. LNCS, vol. 773, pp. 22–39. Springer, Heidelberg (1994)Google Scholar
  3. 3.
    Courtois, N., Meier, W.: Algebraic Attacks on Stream Ciphers with Linear Feedback. In: Biham, E. (ed.) EUROCRYPT 2003. LNCS, vol. 2656, pp. 345–359. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  4. 4.
    Ekdahl, P., Johansson, T., Meier, W.: Predicting the Shrinking Generator with Fixed Connections. In: Biham, E. (ed.) EUROCRYPT 2003. LNCS, vol. 2656, pp. 330–344. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  5. 5.
    Golomb, S.: Shift Register Sequences. Revised edn. Aegean Park Press, Laguna Hills (1982)Google Scholar
  6. 6.
    Gouget, A., Sibert, H.: The bit-search generator. In: The State of the Art of Stream Ciphers: Workshop Record, Brugge, Belgium, October 2004, pp. 60–68 (2004)Google Scholar
  7. 7.
    Krause, M.: BDD-based cryptanalysis of keystream generators. In: Knudsen, L.R. (ed.) EUROCRYPT 2002. LNCS, vol. 2332, pp. 222–237. Springer, Heidelberg (2002)CrossRefGoogle Scholar
  8. 8.
    Meier, W., Staffelbach, O.: The self-shrinking generator. In: De Santis, A. (ed.) EUROCRYPT 1994. LNCS, vol. 950, pp. 205–214. Springer, Heidelberg (1995)CrossRefGoogle Scholar
  9. 9.
    Rueppel, R.A.: Analysis and Design of Stream Ciphers. Springer, Heidelberg (1986)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Aline Gouget
    • 1
  • Hervé Sibert
    • 1
  • Côme Berbain
    • 2
  • Nicolas Courtois
    • 3
  • Blandine Debraize
    • 3
    • 4
  • Chris Mitchell
    • 5
  1. 1.France Telecom Research and DevelopmentCaenFrance
  2. 2.France Telecom Research and DevelopmentIssy-les-MoulineauxFrance
  3. 3.Axalto Cryptographic Research & Advanced SecurityLouveciennes CedexFrance
  4. 4.Versailles UniversityVersaillesFrance
  5. 5.Information Security Group, Royal HollowayUniversity of LondonEghamUnited Kingdom

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