Efficient secret sharing without a mutually trusted authority

Abstract

Traditional secret sharing schemes involve the use of a mutually trusted authority to assist in the generation and distribution of shares that will allow a secret to be protected among a set of participants. In contrast, this paper addresses the problem of establishing a secret sharing scheme for a given access structure without the use of a mutually trusted authority. A general protocol is discussed and several implementations of this protocol are presented. The efficiency of these implementations is considered. The protocol is then refined and constructions are presented for mutually trusted authority free threshold schemes.