Security Analysis and Optimization of AES S-Boxes Against CPA Attack in Wireless Sensor Network

Most of today´s wireless sensor networks use a symmetric-key algorithm such as AES for security. Cryptographic S-boxes are an integral part of the AES, although there existed a rich literature devoted to efficient implementations for them, but little attention has been paid to security aspects of the S-box designs. In this paper we conducted a simulation-based CPA attack on AES implementations with different S-box structures. Our results show that the abilities of AES and S-boxes to secure against CPA attack are correlated, and an evaluation of the ability of S-boxes to thwart CPA is presented in a quantitative way. By further exploiting, a novel byte substitution circuit used inhomogeneous S-boxes instead of fixed S-boxes was proposed, and the simulation result shows that power consumption becomes randomized and the peak corresponding to the correct key is masked successfully.