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Smashing SQUASH-0

Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5479)

Abstract

At the RFID Security Workshop 2007, Adi Shamir presented a new challenge-response protocol well suited for RFIDs, although based on the Rabin public-key cryptosystem. This protocol, which we call SQUASH-0, was using a linear mixing function which was subsequently withdrawn. Essentially, we mount an attack against SQUASH-0 with full window which could be used as a “known random coins attack” against Rabin-SAEP. We then extend it for SQUASH-0 with arbitrary window. We apply it with the proposed modulus 21 277− 1 to run a key recovery attack using 1 024 chosen challenges. Since the security arguments equally apply to the final version of SQUASH and to SQUASH-0, we challenge the blame-game argument for the security of SQUASH. Nevertheless, our attacks are inefficient when using non-linear mixing so the security of SQUASH remains open.

Keywords

RFID cryptanalysis MAC 

References

  1. 1.
    Boneh, D.: Simplified OAEP for the RSA and rabin functions. In: Kilian, J. (ed.) CRYPTO 2001. LNCS, vol. 2139, pp. 275–291. Springer, Heidelberg (2001)CrossRefGoogle Scholar
  2. 2.
    Kipnis, A., Shamir, A.: Cryptanalysis of the HFE public key cryptosystem by relinearization. In: Wiener, M. (ed.) CRYPTO 1999. LNCS, vol. 1666, pp. 19–30. Springer, Heidelberg (1999)CrossRefGoogle Scholar
  3. 3.
    Shamir, A.: SQUASH: A new one-way hash function with provable security properties for highly constrained devices such as RFID tags. In: Invited lecture to the RFID Security 2007 Workshop, http://mailman.few.vu.nl/pipermail/rfidsecuritylist/2007-August/000001.html
  4. 4.
    Shamir, A.: SQUASH – A new MAC with provable security properties for highly constrained devices such as RFID tags. In: Nyberg, K. (ed.) FSE 2008. LNCS, vol. 5086, pp. 144–157. Springer, Heidelberg (2008)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  1. 1.EPFLLausanneSwitzerland

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