Cycle Structure and Observability of Two Types of Galois NFSRs

ePrint Report: Cycle Structure and Observability of Two Types of Galois NFSRs

Xianghan Wang, Jianghua Zhong, Dongdai Lin

Nonlinear feedback shift registers (NFSRs) are used in many stream ciphers as their main building blocks. One security criterion for the design of a stream cipher is to assure its keystream has a long period. To meet this criterion, the NFSR used in a stream cipher must have a long state cycle. Further, to simultaneously avoid equivalent keys, the keystream's period is …

building cipher ciphers design eprint report feedback main observability report security stream stream cipher structure types wang zhong