A Share-Correctable Protocol for the Shamir Threshold Scheme and Its Application to Participant Enrollment

Abstract

Verifiable secret sharing schemes proposed so far can only allow participants to verify whether their shares are correct or not. In this paper, we propose a new protocol which can allow participants not only to verify the correctness of their shares but also to revise the faulty shares. It is achieved in a cooperative way by participants, but without any assistance from the dealer. This protocol, to the best of our knowledge, is the first one providing such kind of ability. Correcting shares by participants instead of the dealer is important in many situations. In addition, this protocol is also useful for adding new participants without the dealer's assistance.