How to Find Short RC4 Colliding Key Pairs

  • Jiageng Chen
  • Atsuko Miyaji
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7001)


The property that the stream cipher RC4 can generate the same keystream outputs under two different secret keys has been discovered recently. The principle that how the two different keys can achieve a collision is well known by investigating the key scheduling algorithm of RC4. However, how to find those colliding key pairs is a different story, which has been largely remained unexploited. Previous researches have demonstrated that finding colliding key pairs becomes more difficult as the key size decreases. The main contribution of this paper is proposing an efficient searching algorithm which can successfully find 22-byte colliding key pairs, which are by far the shortest colliding key pairs ever found.


Stream Cipher Message Block Brute Force Search Wire Equivalent Privacy Hash Collision 
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.
  2. 2.
    Matsui, M.: Key Collisions of the RC4 Stream Cipher. In: Dunkelman, O., Preneel, B. (eds.) FSE 2009. LNCS, vol. 5665, pp. 38–50. Springer, Heidelberg (2009)CrossRefGoogle Scholar
  3. 3.
    Chen, J., Miyaji, A.: Generalized RC4 Key Collisions and Hash Collisions. In: Garay, J.A., De Prisco, R. (eds.) SCN 2010. LNCS, vol. 6280, pp. 73–87. Springer, Heidelberg (2010)CrossRefGoogle Scholar
  4. 4.
    Chen, J., Miyaji, A.: A New Practical Key Recovery Attack on the Stream Cipher RC4 Under Related-Key Model. In: Lai, X., Yung, M., Lin, D. (eds.) Inscrypt 2010. LNCS, vol. 6584, pp. 62–76. Springer, Heidelberg (2011)CrossRefGoogle Scholar
  5. 5.
    Sepehrdad, P., Vaudenay, S., Vuagnoux, M.: Statistical Attack on RC4. In: Paterson, K. (ed.) EUROCRYPT 2011. LNCS, vol. 6632, pp. 343–363. Springer, Heidelberg (2011)CrossRefGoogle Scholar
  6. 6.
    Sepehrdad, P., Vaudenay, S., Vuagnoux, M.: Discovery and Exploitation of New Biases in RC4. In: Biryukov, A., Gong, G., Stinson, D. (eds.) SAC 2010. LNCS, vol. 6544, pp. 74–91. Springer, Heidelberg (2011)CrossRefGoogle Scholar
  7. 7.
    Maitra, S., Paul, G., Sen Gupta, S.: Attack on Broadcast RC4 Revisited. In: Joux, A. (ed.) FSE 2011. LNCS, vol. 6733, pp. 199–217. Springer, Heidelberg (2011)CrossRefGoogle Scholar
  8. 8.
    Wang, X., Yu, H.: How to break MD5 and other hash functions. In: Cramer, R. (ed.) EUROCRYPT 2005. LNCS, vol. 3494, pp. 19–35. Springer, Heidelberg (2005)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Jiageng Chen
    • 1
  • Atsuko Miyaji
    • 1
  1. 1.School of Information ScienceJapan Advanced Institute of Science and TechnologyNomiJapan

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