MODELLING THE SHRINKING GENERATOR IN TERMS OF LINEAR CA

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Author(s):	Cardell, Sara D. ; Fuster-Sabater, Amparo Total Authors: 2
Document type:	Journal article
Source:	Advances in Mathematics of Communications; v. 10, n. 4, p. 797-809, NOV 2016.
Web of Science Citations:	5
Abstract
This work analyses the output sequence from a cryptographic non-linear generator, the so-called shrinking generator. This sequence, known as the shrunken sequence, can be built by interleaving a unique PN-sequence whose characteristic polynomial serves as basis for the shrunken sequence's characteristic polynomial. In addition, the shrunken sequence can be also generated from a linear model based on cellular automata. The cellular automata here proposed generate a family of sequences with the same properties, period and characteristic polynomial, as those of the shrunken sequence. Moreover, such sequences appear several times along the cellular automata shifted a fixed number. The use of discrete logarithms allows the computation of such a number. The linearity of these cellular automata can be advantageously employed to launch a cryptanalysis against the shrinking generator and recover its output sequence. (AU)

FAPESP's process:	15/07246-0 - Construction, decoding and implementation of F_q linear codes. Performanca of SPC product codes and cryptanalysis of the shrinking generators.
Grantee:	Sara Díaz Cardell
Support Opportunities:	Scholarships in Brazil - Post-Doctoral