International Association
for Cryptologic Research

In this paper, we present several efficient fault attacks against implementations of RSA-CRT signatures that use modular exponentiation algorithms based on Montgomery multiplication. They apply to any padding function, including randomized paddings, and as such are the

first fault attacks effective against RSA-PSS.

The new attacks work provided that a small register can be forced to either zero, or a constant value, or a value with zero high-order bits. We show that these models are quite realistic, as such faults can be achieved against many proposed hardware designs for RSA signatures.