PSS Is Secure against Random Fault Attacks

A fault attack consists in inducing hardware malfunctions in order to recover secrets from electronic devices. One of the most famous fault attack is Bellcore’s attack against RSA with CRT; it consists in inducing a fault modulo p but not modulo q at signature generation step; then by taking a gcd the attacker can recover the factorization of N = pq. The Bellcore attack applies to any encoding function that is deterministic, for example FDH. Recently, the attack was extended to randomized encodings based on the iso/iec 9796-2 signature standard. Extending the attack to other randomized encodings remains an open problem. In this paper, we show that the Bellcore attack cannot be applied to the PSS encoding; namely we show that PSS is provably secure against random fault attacks in the random oracle model, assuming that inverting RSA is hard. Key-words: Probabilistic Signature Scheme, Provable Security, Fault Attacks, Bellcore Attack.