Design and implementation of power analysis-immune SMS4 algorithm

This paper presents a new architecture and circuit implementation of low-cost power analysis-immune SMS4. The general data masking scheme is used in the liner operations of SMS4, such as cyclic left shift and exclusive OR. For the nonliner operation, inhomogeneous S-boxes instead of fixed S-boxes are designed, which show different power consumption curves. The permutation of S-boxes is determined by using the circular left shifter and the circular right shifter, which lead to SMS4 operation power randomization. The experimental results demonstrate that this method enhance the SMS4 secure characteristics effectually against the power analysis attack.