Shrinking generators based on sigma-LFSRs

摘要

The word-based LFSRs called sigma-LFSRs are very attractive as they take advantage of the modern word-based processor and thus increase the throughput. Secondly, the bitstream produced by sigma-LFSR has excellent statistical properties with a high period except for low linear complexity. In order to increase the linear complexity, the concept of both bit-oriented shrinking and self-shrinking generators is introduced in case of sigma-LFSRs. In both the cases, the lower bound for the period as well as for the linear complexity of the bitstream are shown to be exponential. Further, we have experimented and investigated more results on the periodicity and statistical properties of the bitstream in self-shrinking sigma-LFSRs. This helps to find and prove the exact period of the bitstream produced by self-shrinking generators. (C) 2020 Elsevier B.V. All rights reserved.