New Fault-Based Side-Channel Attack Using Fault Sensitivity

This paper proposes a new fault-based attack called fault sensitivity analysis (FSA) attack. In the FSA attack, fault injections are used to test out the sensitive information leakage called fault sensitivity. Fault sensitivity means the critical fault injection intensity that corresponds to the threshold between devices' normal and abnormal behaviors. We demonstrate that without using the values of the faulty outputs, attackers can obtain the information of the secret key based on the data-dependency of the collected fault sensitivity data. This paper explains the successful FSA attacks against three Advanced Encryption Standard (AES) hardware implementations, where two of them are resistant to the differential fault analysis. This paper also discusses the countermeasures against the proposed FSA attacks.