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A Linear Analysis of Blowfish and Khufu

  • Jorge NakaharaJr.
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4464)

Abstract

This paper describes a linear analysis of Blowfish (a block cipher designed by B. Schneier in 1993), and Khufu (a cipher designed by R.C. Merkle in 1989). The nonlinear cipher components of these ciphers are key dependent, and thus, unknown to unauthorized entities. Nonetheless, we estimate the fraction of user keys that generate weak nonlinear components (namely, with large enough bias). As far as we are aware of this paper reports the first known-plaintext (and ciphertext-only) attacks on these ciphers.

Keywords

Blowfish Khufu linear cryptanalysis key-dependent S- boxes 

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Copyright information

© Springer Berlin Heidelberg 2007

Authors and Affiliations

  • Jorge NakaharaJr.
    • 1
  1. 1.UNISANTOSBrazil

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