Exposure - Resilient Cryptography 7 February 2007 Lecture 4 Lecturer :

In this lecture, we give a high-level tour of DL-Based Threshold Cryptography. We begin with distributed generation of discrete log keys. We describe two protocols: (1) parallel Feldman and its (limited) security properties – good for adaptive Pedersen VSS, but not when the simulator needs to force the outcome (due to rushing), and (2) parallel Pedersen followed by the first protocol. Next, we describe BLS signatures and their threshold variant. Finally, we describe ElGamal encryption and its threshold variant, which uses an HVZK proof of equality of discrete logs.