On-line error detection and BIST for the AES encryption algorithm with different S-box implementations

Abstract

In this paper we experimentally investigate the efficiency of concurrent checking for the AES encryption algorithm (Rijndael) by parity modification according to K. Wu et al. (2004). Also we propose a simple BIST method. For BIST the implementation of the AES algorithm itself is used as well as a pseudo-random test input generator and a compactor of the test results. Thereby we utilized the property of the AES algorithm that arbitrarily given plain texts are encrypted by the successive rounds into "pseudo-random" cipher texts which are the (test) inputs for the next round. The complete data path of the AES algorithm is simulated as a netlist of AND-, NAND-, OR-, NOR- and XOR-gates. All possible single stuck-at faults are injected and simulated. For a special implementation of the S-boxes all errors within the data path of the AES algorithm due to single stuck-at faults are immediately detected.