Publicly verifiable secret sharing

Abstract

A secret sharing scheme allows to share a secret among sev- eral participants such that only certain groups of them can recover it. Verifiable secret sharing has been proposed to achieve security against cheating participants. Its first realization had the special property that everybody, not only the participants, can verify that the shares are cor- rectly distributed. We will call such schemes publicly verifiable secret sharing schemes, we discuss new applications to escrow cryptosystems and to payment systems with revocable anonymity, and we present two new realizations based on ElGamal’s cryptosystem.