International Conference on the Theory and Applications of Cryptographic Techniques

EUROCRYPT 1998: Advances in Cryptology — EUROCRYPT'98 pp 319-333

Towards a better understanding of one-wayness: Facing linear permutations

  • Alain P. Hiltgen
Conference paper

DOI: 10.1007/BFb0054136

Volume 1403 of the book series Lecture Notes in Computer Science (LNCS)

Abstract

The one-wayness of linear permutations, i.e., invertible linear Boolean functions F: {0,1}n → {0, 1}n, is investigated. For linear permutations with a triangular matrix description (tlinear permutations), we prove that one-wayness, C(F−1)/C(F), is non-trivially upperbounded by 16√n, where C(.) denotes unrestricted circuit complexity. We also prove that this upper bound strengthens as the complexity of the inverse function increases, limiting the one-wayness of t-linear permutations with C(F−1) = n2/(c log2(n)) to a constant, i.e., a value that is independent of n. Direct implications for linear and also non-linear permutations are discussed. Moreover, and for the first time ever, a description is given about where, in the case of linear permutations, practical one-wayness would have to come from, if it exists.

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Copyright information

© Springer-Verlag 1998

Authors and Affiliations

  • Alain P. Hiltgen
    • 1
  1. 1.UBS - Corporate IT SecurityZurichSwitzerland