Alberto Battistiello (Oberthur, UVSQ).
Common Points on Elliptic Curves: The Achille's heel of fault attack countermeasures.
Elliptic curve cryptosystems offer many advantages over RSA-like cryptography, such as speed and memory saving. Nonetheless the advent of side-channel and fault-injection attacks mined the security of such implementations. Several countermeasures have been devised to thwart these threats, so that simple attacks on state-of-the-art secured implementations seem unlikely. We took up the challenge and show that a simple fault attack using a very relaxed fault model can defeat well known countermeasures. After introducing the notion of common points, we exhibit a new fault-injection attack that breaks state-of-the-art secured implementations. Our new attack is particularly dangerous since no control on the injected error is required and only one fault is sufficient to retrieve the secret.