KTH - Royal Institute of Technology
Non-Linear Feedback Shift Registers (NLFSRs) are a generalization of Linear Feedback Shift Registers (LFSRs) in which a current state is a nonlinear function of the previous state. While the theory behind LFSRs is well-understood, many fundamental problems related to NLFSRs remain open. Probably the most important one is finding a systematic procedure for constructing NLFSRs with a guaranteed long period. Available algorithms either consider some special cases, or are applicable to small NLFSRs only. Linear Feedback Shift Registers (LFSRs) are one of the most popular devices for generating pseudo-random sequences.