Paper 2012/257

The Transformation from the Galois NLFSR to the Fibonacci Configuration

Lin Zhiqiang

Abstract

The Galois configuration of Nonlinear Feedback Shift Registers (NLFSRs) is attractive for stream ciphers for which high throughput is very important. In this paper, we prove that any Galois NLFSR can be transformed into an equivalent NLFSR in the Fibonacci configuration, which is the conventional conguration of NLFSRs. The transformation is mentioned in the proof. The mapping between the initial states of the Galois NLFSR and its equivalent Fibonacci configuration is also derived. Moreover, some properties of Galois NLFSRs are presented.