Welcome to the resource topic for 2015/495
Title:
Powers of Subfield Polynomials and Algebraic Attacks on Word-Based Stream Ciphers
Authors: Sondre Rønjom
Abstract:In this paper we investigate univariate algebraic attacks on filter generators over extension fields \F_q=\F_{2^n} with focus on the Welch-Gong (WG) family of stream ciphers. Our main contribution is to break WG-5, WG-7, WG-8 and WG-16 by combining results on the so-called spectral immunity (minimum distance of certain cyclic codes) with properties of the WG type stream cipher construction. The spectral immunity is the univariate analog of algebraic immunity and instead of measuring degree of multiples of a multivariate polynomial, it measures the minimum number of nonzero coefficients of a multiple of a univariate polynomial. Based on the structure of the general WG-construction, we deduce better bounds for the spectral immunity and the univariate analog of algebraic attacks.
ePrint: https://eprint.iacr.org/2015/495
See all topics related to this paper.
Feel free to post resources that are related to this paper below.
Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.
For more information, see the rules for Resource Topics .