Designing a keystream generator which utilizes Linear Feedback
Shift Registers (LFSRs) against correlation, linear attacks is a highly
challenging task. In this paper, a new framework for keystream gen-
erators is proposed. It is comprised of a set of Linear Feedback Shift
Registers (LFSRs), a Multiplicative Congruential Generator (MCG),
a vector linear function and, a Boolean function which outputs the
keystream. The framework is more generally discussed against corre-
lation attacks, linear attacks and distinguishing (linear) attacks. It is shown that such attacks which are applicable to LFSR based keystream
generators are not possible on the proposed framework.
↧