Design of an Instruction for Fast and Efficient S-Box Implementation

With the development of cipher instruction set extension, design of s-box instruction has received more and more attention. An s-box instruction named SboxPer is designed in this paper for fast and efficient implementation of s-boxes in common symmetric-key ciphers. By introducing PLUT, this instruction improves the efficiency of table lookup. Half-byte permutation is performed after the table lookup operation, which leads to the result that no additional instruction is needed to obtain the final result of S-box operation. Results of performance estimate show that this instruction can improve the execution speed of s- box lookup in symmetric-key ciphers significantly and occupies little memory space.