A COMPARATIVE STUDY OF VERIFIABLE SECRET SHARING SCHEMES

Abstract

In recent decades, many researchers have investigated peer-to-peer security and cryptography such as symmetric encryption, public-key encryption, hashing and digital signature. These tech .iques can protect private communications between two parties securely in a public channel. Since the Internet and networking have become more and more popular, many people have started to investigate security between groups of people such as a Secret Sharing Scheme. Secret Sharing is the process of distributing a secret key amongst several participants so that only certain subsets of these participants can recover any information about the key. Verifiable Secret Sharing (VSS) is a stronger notion than standard secret sharing in that it should provide robustness against actively cheating players. This dissertation deals with four Verifiable Secret Sharing schemes. They are Ben-Or/Rabin Scheme, Feldman Scheme, Pederson Scheme and the fourth one is a new protocol developed by us that can be proved as the most cost-effective solution of all Verifiable Secret Sharing Schemes. The performances of all the schemes are studied with the performance indices being file size of individual user shares and probability that cheating cannot be detected. Even improved versions of Feldman and Pederson Schemes (using GF4 Multiplication) are presented and their advantages and limitations are discussed. All the Schemes are implemented in Java across a network using Java Sockets in Windows XP environment