A Simple Algorithm for Fast Correlation Attacks on Stream Ciphers

  • Vladimor V. Chepyzhov
  • Thomas Johansson
  • Ben Smeets
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1978)


A new simple algorithm for fast correlation attacks on stream ciphers is presented. The advantages of the new approach are at least two. Firstly, the new algorithm significantly reduces the memory requirements compared with some recent proposals [2],[3]. This allows more powerful attacks than previously. Secondly, the simplicity of the algorithm allows us to derive theoretical results. We determine the relation between the number of observed symbols, the correlation probability, and the allowed computational complexity, required for a successful attack. Hence, we can get theoretical estimates on the required computational complexity in cases when simulation is not possible.


Stream ciphers correlation attacks cryptanalysis 


  1. 1.
    T. Siegenthaler, “Decryptinga class of stream ciphers usingciphertext only”, IEEE Trans. Comput., Vol. C-34, pp. 81–85, 1985.CrossRefGoogle Scholar
  2. 2.
    T. Johansson, F. Jönsson, “Improved fast correlation attacks on stream ciphers via convolutional codes”, Proceedings of EUROCRYPT’99, Springer-Verlag, LNCS 1592, pp. 347–362.Google Scholar
  3. 3.
    T. Johansson, F. Jönsson, “Improved fast correlation attacks on stream ciphers via convolutional codes”, Proceedings of CRYPTO’99, Springer-Verlag, LNCS 1666, pp. 181–197.Google Scholar
  4. 4.
    W. Meier, and O. Staffelbach, “Fast correlation attacks on certain stream ciphers”, J. Cryptology, pp. 159–176, 1989.Google Scholar
  5. 5.
    M. Mihaljevic, and J.Dj. Golić, “A fast iterative algorithm for a shift register initial state reconstruction given the noisy output sequence”, Proc. Auscrypt’90, Springer-Verlag, LNCS 453, Eds. J. Seberry and J. Pieprzyk, pp. 165–175, 1990.Google Scholar
  6. 6.
    V. Chepyzhov, and B. Smeets, “On a fast correlation attack on stream ciphers”, Adv. Crypt.-EUROCRYPT’91, Brighton, UK, Springer-Verlag, LNCS 547, Ed, D.W. Davies, pp. 176–185, 1991.Google Scholar
  7. 7.
    J.Dj. Golić, “Computation of low-weight parity-check polynomials”, Electronic Letters, Vol.32,No. 21, Oct., pp. 1981–1982, 1996.CrossRefGoogle Scholar
  8. 8.
    R.G. Gallager, Information Theory and Reliable Communications, John Wiley and Sons, Inc. New York, London, Sydney, Toronto, 1968.Google Scholar
  9. 9.
    F. MacWilliams, N. Sloane, The theory of error correcting codes, North Holland, 1977.Google Scholar
  10. 10.
    W. Penzhorn, “Correlation attacks on stream ciphers: Computinglo w weight parity checks based on error correcting codes”, FSE’96, Springer-Verlag, LNCS 1039, pp. 159–172.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Vladimor V. Chepyzhov
    • 1
  • Thomas Johansson
    • 2
  • Ben Smeets
    • 3
  1. 1.Institute for Problems of Information TransmissionRussian Academy of SciencesMoscowRussia
  2. 2.Dept. of Information TechnologyLund UniversityLundSweden
  3. 3.Ericsson Mobile CommunicationsLundSweden

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