The Cryptanalysis of LFSR/FCSR Based Alternating Step Generator
Shun‐Lung Su, Ko-Ming Chiu, Lih‐Chyau Wuu · 2006
The alternating step generator (ASG) was proposed by Gunther in 1988 and consists of three LFSRs. After several serious attacks to ASG were proposed in recent years, the security of ASG has been carefully reexamined. A new structure of LFSR/FCSR based ASG and a new combination function are proposed in this research. Here, the structures of LFSR/FCSR based ASG are found to have lower probability of finding the corresponding pairs of two base sequences from an output sequence. In other words, it can resist edit distance correlation attacks efficiently. From the overall evaluation in this research, the structures of LFSR/FCSR based ASG are regarded to be more secure than ASG