A Compact S-Box Design for SMS4 Block Cipher

Abstract

Abstract. This paper proposes a compact design of SMS4 S-box using combinational logic which is suitable for the implementation in area constraint environments like smart cards. The inversion algorithm of the proposed S-box is based on composite field GF(((2 2 ) 2 ) 2 ) using normal basis at all levels. In our approach, we examined all possible normal basis combinations having trace equal to one at each subfield level. There are 16 such possible combinations with normal basis and we have compared the S-box designs based on each case in terms of logic gates it uses for implementation. The isomorphism mapping and inverse mapping bit matrices are fully optimized using greedy algorithm. We prove that our best case reduces the complexity upon the SMS4 S-box design with existing inversion algorithm based on polynomial basis by 15% XOR and 42% AND gates.

Performance evaluation of the SM4 cipher based on field‐programmable gate array implementation

“…Many researchers have focused on optimising the SM4 cipher for achieving low area use [7,[9][10][11][12][13][14][15][16]. Others have concentrated on implementing high throughput designs [8,[11][12][13][14][16][17][18].…”