Cheating prevention in secret sharing

Abstract

The commonly used technique for cheating detection requires that extra information be given to each participant. However, in a secret sharing scheme when the size of shares increases the security of the system degrades. In this paper we study the cheating problem in Shamir's scheme(in the sense of Tompa and Woll attack) and present alternative solutions to this problem. First we consider cheating prevention via longer shares. Next we introduce redundant secret sharing schemes and show how they can be used for cheating prevention. Nonlinear secret sharing offers also some protection against cheaters. The work concludes with a discussion about a combined approach.