Design of a New Stream Cipher—LEX

  • Alex Biryukov
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4986)


In this paper we define a notion of leak extraction from a block cipher. We demonstrate this new concept on an example of AES. A result is LEX: a simple AES-based stream cipher which is at least 2.5 times faster than AES both in software and in hardware.


Block Cipher Advance Encryption Standard Stream Cipher Stream Generation Algebraic Attack 
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.


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  1. 1.
    Babbage, S.: Improved “exhaustive search” attacks on stream ciphers. In: Babbage, S. (ed.) ECOS 1995 (European Convention on Security and Detection). IEE Conference Publication, vol. 408 (May 1995)Google Scholar
  2. 2.
    Biham, E.: How to decrypt or even substitute DES-encrypted messages in 228 steps. Information Processing Letters 84, 117–124 (2002)zbMATHCrossRefMathSciNetGoogle Scholar
  3. 3.
    Biryukov, A., Mukhopadhyay, S., Sarkar, P.: Improved Time-Memory Trade-offs with Multiple Data. In: Preneel, B., Tavares, S. (eds.) SAC 2005. LNCS, vol. 3897, pp. 110–127. Springer, Heidelberg (2006)CrossRefGoogle Scholar
  4. 4.
    Biryukov, A., Shamir, A.: Cryptanalytic time/memory/data tradeoffs for stream ciphers. In: Okamoto, T. (ed.) ASIACRYPT 2000. LNCS, vol. 1976, pp. 1–13. Springer, Heidelberg (2000)CrossRefGoogle Scholar
  5. 5.
    Biryukov, A., Wagner, D.: Slide attacks. In: Knudsen, L.R. (ed.) FSE 1999. LNCS, vol. 1636, pp. 245–259. Springer, Heidelberg (1999)CrossRefGoogle Scholar
  6. 6.
    Courtois, N.T., Meier, W.: Algebraic attacks on stream ciphers with linear feedback. In: Biham, E. (ed.) Advances in Cryptology – EUROCRYPT 2003. LNCS, pp. 345–359. Springer, Heidelberg (2003)Google Scholar
  7. 7.
    Daemen, J., Rijmen, V.: The design of Rijndael: AES — The Advanced Encryption Standard. Springer, Heidelberg (2002)zbMATHGoogle Scholar
  8. 8.
    eSTREAM, eSTREAM Optimized Code HOWTO (2005),
  9. 9.
    Golic, J.D.: Cryptanalysis of alleged A5 stream cipher. In: Fumy, W. (ed.) EUROCRYPT 1997. LNCS, vol. 1233, pp. 239–255. Springer, Heidelberg (1997)Google Scholar
  10. 10.
    Hong, J., Sarkar, P.: Rediscovery of time memory tradeoffs (2005),
  11. 11.
    Wu, H., Preneel, B.: Attacking the IV Setup of Stream Cipher LEX. In: Robshaw, M.J.B. (ed.) FSE 2006. LNCS, vol. 4047. Springer, Heidelberg (2006)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Alex Biryukov
    • 1
  1. 1.University of Luxembourg, FSTCLuxembourg-KirchbergLuxembourg

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