On Distributed Key Distribution Centers and Unconditionally Secure Proactive Verifiable Secret Sharing Schemes Based on General Access Structure

A Key Distribution Center of a network is a server enabling private communications within groups of users. A Distributed Key Distribution Center is a set of servers that jointly realizes a Key Distribution Center. In this paper we build a robust Distributed Key Distribution Center Scheme secure against active and mobile adversary. We consider a general access structure for the set of servers and for the adversary access structure. We also revise the unconditionally secure Verifiable Secret Sharing Schemes from [11, 10, 20, 23] proposing a modified version which is proactively secure.