Shafi Goldwasser Yael Tauman Kalai On the (In)security of the Fiat-Shamir Paradigm. 102-113 2003 conf/focs/2003 FOCS http://doi.ieeecomputersociety.org/10.1109/SFCS.2003.1238185 db/conf/focs/focs2003.html#GoldwasserK03