Secure classical RSA Cryptosystem against Fault Injection Attack based on Fermat's Theorem

Esmbedded devices such as smart cards and electronic passports highly demand security of sensitive data. So, the secure implementation of the cryptographic system against various side -channel attacks are becoming more important. In particular, th e fault injection attack is one of the threats to the cryptosystem and can destroy the whole system only with single pair of the plain and cipher texts. Therefore, the implementors must consid er seriously the attack. Several techniques for preventing fault injection attacks were introduced to a variety of the cryptosys tem, But the countermeasures are still inefficient to be applied to the classical RSA cryptosystem. This paper introduces an efficient countermeasure against the fault injection attack for the classical RSA cryptosystem, which is based on the famous Fermat 's theorem. The proposed countermeasure has the advantage that it has less computational overhead, compared with the previous countermeasures. Keywords: classical RSA, Fault Injection Attack, Fermat's Theorem