Theoretical cryptanalysis of the Klimov-Shamir number generator TF-1

Boaz Tsaban

doi:10.1007/s00145-007-0564-4

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Theoretical cryptanalysis of the Klimov-Shamir number generator TF-1

Boaz Tsaban

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Abstract

The internal state of the Klimov-Shamir number generator TF-1 consists of four words of size w bits each, whereas its intended strength is 2^{2w}. We exploit an asymmetry in its output function to show that the internal state can be recovered after having 2^w outputs, using 2^{1.5w} operations. For w=32 the attack is practical, but for their recommended w=64 it is only of theoretical interest.

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BibTeX RIS

Boaz Tsaban. 2007-05-20. Theoretical cryptanalysis of the Klimov-Shamir number generator TF-1. https://doi.org/10.1007/s00145-007-0564-4

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