The Last Challenge Attack: Exploiting a Vulnerable Implementation of the Fiat-Shamir Transform in a KZG-based SNARK

ePrint Report: The Last Challenge Attack: Exploiting a Vulnerable Implementation of the Fiat-Shamir Transform in a KZG-based SNARK

Oana Ciobotaru, Vesselin Velichkov, Maxim Peter

The Fiat-Shamir transform [1] is a well-known and widely employed technique for converting sound public-coin interactive protocols into sound non-interactive protocols. Even though the transformation itself is relatively clear and simple, some implementations choose to deviate from the specifications, for example for performance reasons. In this short note, we present a vulnerability arising from such a …

attack challenge eprint report exploiting fiat implementation non peter protocols public report sound transform vulnerable well-known