Fault Detection Structures of the S-boxes and the Inverse S-boxes for the Advanced Encryption Standard

Fault detection schemes for the Advanced Encryption Standard are aimed at detecting the internal and malicious faults in its hardware implementations. In this paper, we present fault detection structures of the S-boxes and the inverse S-boxes for designing high performance architectures of the Advanced Encryption Standard. We avoid utilizing the look-up tables for implementing the S-boxes and the inverse S-boxes and their parity predictions. Instead, logic gate implementations based on composite fields are used. We modify these structures and suggest new fault detection schemes for the S-boxes and the inverse S-boxes. Using the closed formulations for the predicted parity bits, the proposed fault detection structures of the S-boxes and the inverse S-boxes are simulated and it is shown that the proposed schemes detect all single faults and almost all random multiple faults. We have also synthesized the modified S-boxes, inverse S-boxes, mixed S-box/inverse S-box structures, and the whole AES encryption using the 0.18 μ CMOS technology and have obtained the area, delay, and power consumption overheads for their fault detection schemes. Furthermore, the fault coverage and the overheads in terms of the space complexity and time delay are compared to those of the previously reported ones.