Civitas: Implementation of a Threshold Cryptosystem

Abstract

This paper describes the implementation of a threshold cryptosystem for Civitas, a secure electronic voting system. The cryptosystem improves the availability of Civitas by enabling tabulation to complete despite the failure of some agents. The implementation includes a sophisticated distributed key generation protocol, which was designed by Gennaro, Jarecki, Krawczyk, and Rabin. The cryptosystem is implemented in Jif, a security-typed language.