On Equivalence Relations of State Diagram of Cascade Connection of an LFSR into an NFSR

摘要

Grain is one of the hardware-oriented finalists of the eSTREAM. The cipher has a cascade connection of an LFSR into an NFSR which is denoted by Cascade Model. In this paper, we study the equivalence relations between state diagrams of two functions, and apply them to the Cascade Models, then some results regarding their equivalence relations are obtained.