Generation of Nonlinear Feedback Shift Registers with Special-Purpose Hardware
The NonLinear Feedback Shift Registers (NLFSR) are used to construct pseudorandom generators for stream ciphers. Their theory is not so complete as that of the Linear Feedback Shift Registers (LFSR). In general, it is not known how to construct NLFSRs with maximum period. The direct method is to search for such registers with suitable properties. The authors used the implementation of NLFSRs in Field Programmable Gate Arrays (FPGA) to perform a corresponding search. They also investigated local statistical properties of the binary sequences generated by NLFSRs of order 25 and 27.