期刊名称：International Journal of Computer Science and Information Technologies
电子版ISSN：0975-9646
出版年度：2016
卷号：7
期号：6
页码：2526-2530
出版社：TechScience Publications
摘要：Convolution Code based Fast Correlation Attacks(FCA) are a powerful class of attacks on stream ciphers. Thusstream ciphers are designed so that combiner function iscorrelation immune. In this paper we propose a method toapply Convolution Code based FCA when the combinerfunction is first order correlation immune (1-CI) but not 2-CI.We apply the attack on a pair of LFSRs whose sum sequenceis correlated to key-stream. Instead of directly computingparity checks of equivalent LFSR for the sum sequence, wecollect the parity checks of the individual LFSRs into two setsand from the cross product of the set of parity checks, selectthose pairs in which the two highest degree terms in both theparity checks are identical. These pairs of parity checks areused for setting up the Viterbi decoding phase of the FCA.The proposed method is more efficient than the directFCA using the product of feedback polynomials of LFSRs
