A Structure-independent Approach for Fault Detection Hardware Implementations of the Advanced Encryption Standard

The Advanced Encryption Standard, which is used extensively for secure communications, has been accepted recently as a symmetric cryptography standard. However, occurrence of the internal faults by intrusion of the attackers may cause confidential information leak to reveal the secret key. For this reason, several schemes for fault detection of the transformations and rounds in the encryption and decryption of the Advanced Encryption Standard are proposed. In this paper, we present a structure-independent fault detection scheme for the Advanced Encryption Standard. The proposed scheme is independent of the way S- box (inverse S-box) is constructed and can be used for both encryption and decryption. It can be applied to both the S-boxes (and inverse S-boxes) using look-up tables as well as those utilizing logic gate implementations based on composite fields. We have obtained the formulations for the fault detection of the SubBytes (inverse SubBytes) using the relation between the input and output of the S-box (inverse S-box). Then, we have proposed and simulated a signature-based structure-independent fault detection scheme. Moreover, the FPGA implementations of the original and the proposed schemes as well as their overhead are presented.