Adaptively-secure optimal-resilience proactive rsa

Abstract

When attacking a distributed protocol, an adaptive adversary may determine its actions (e.g., which parties to corrupt), at any time, based on its entire view of the protocol including the entire communication history. In this paper we are concerned with proactive RSA protocols, i.e., robust distributed RSApro tocols that rerandomize key shares at certain intervals to reduce the threat of long-term attacks. Here we design the first proactive RSAsy stem that is secure against an adaptive adversaries. The system achieves "optimal-resilience" and "secure space scalability" (namely O(1) keys per user).