The optimal key estimation of stream ciphers and its approximation algorithm based on a probabilistic inference

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1 Citation (Scopus)

Abstract

A stream cipher is an important class of encryption algorithms. Its safety depends on the structure of the pseudorandom number generator used. There are various types of pseudo-random number generators in existence, and attack algorithms used on them have been studied individually. In this paper, we express the problem of attacks on a general stream cipher as a probabilistic inference problem, and formulate the optimal key estimation. We also propose a unified framework of attack algorithms that can be applied to a wide variety of stream ciphers. The optimal key estimation, however, has computational complexity. To reduce the complexity, an approximation algorithm based on a probabilistic inference is proposed. We also describe some attack algorithms used on practical pseudorandom number generators. Finally, the proposed algorithm is evaluated by through a computer simulation.

Original languageEnglish
Title of host publication2012 International Symposium on Information Theory and Its Applications, ISITA 2012
Pages531-535
Number of pages5
Publication statusPublished - 2012
Event2012 International Symposium on Information Theory and Its Applications, ISITA 2012 - Honolulu, HI
Duration: 2012 Oct 282012 Oct 31

Other

Other2012 International Symposium on Information Theory and Its Applications, ISITA 2012
CityHonolulu, HI
Period12/10/2812/10/31

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ASJC Scopus subject areas

  • Computer Science Applications
  • Information Systems

Cite this

Iikubo, Y., Horii, S., & Matsushima, T. (2012). The optimal key estimation of stream ciphers and its approximation algorithm based on a probabilistic inference. In 2012 International Symposium on Information Theory and Its Applications, ISITA 2012 (pp. 531-535). [6400993]