Paper 2009/388

A Simple Secret Sharing Scheme for Hierarchical Threshold Access Structures

Kerem Kaskaloglu and Ferruh Ozbudak

Abstract

One of the recent generalizations of (t; n) secret sharing for hierarchical threshold secret access structures is given by Tassa, where he answer the natural question of sharing a secret among three employ- ees at least one of which is a manager. However, the schemes proposed to address this problem, require some significant amount of theoreti- cal background. We give a simpler yet efficient method for hierarchical threshold access structures. Our scheme employs a different approach than previous works, as it involves a certain distribution of polynomi- als, where members of higher compartments are given a summation of evaluations of higher number of polynomials resulting in a hierarchical effect. The simplicity of our scheme is advantageous both in theory and in practical implementations.