Traitor-traceable key pre-distribution based on visual secret sharing

Abstract

In this paper, we study the problem of traitor-traceable key pre-distribution for general access structures. We propose a new scheme for key pre-distribution using visual secret sharing, where the keys are generated based on certain combinatorial block designs. Our scheme naturally extends for general access structures, and provides a flexible many-to-one function using visual secret sharing concepts to efficiently avoid the problem of pixel expansion. In addition, our proposal accommodates a simple traitor-tracing functionality for video broadcast applications; using efficient PBIBD based combinatorial constructs and visual secret sharing based on random grids. In effect, our scheme provides a novel technique for secure video and image broadcast, using general access structures to reduce collusions, trace forgery, and identify traitors in case there is a collusion. We duly analyze and discuss the efficiency of our scheme for varying number of users in the broadcast network. � 2013 Springer-Verlag.