Consensus-Based Secret Sharing in Blockchain Smart Contracts

Abstract

Smart contracts on a blockchain permit the performance of credible transactions without the involvement or oversight of a third party. In some industries such as finance, confidentiality is paramount to protect business-critical information from becoming public; however, in a smart contract, information needs to be known and independently verified. A zero-knowledge proof (ZKP) can be used to obscure this information when there are only two parties in the contract; however, ZKPs do not have a mechanism to handle situations in which multiple parties are involved. We introduce, discuss, and simulate a consensus-based secret sharing protocol which provides zero knowledge of personal information, only allows members to participate if they have a key, and only works when a specified number of members “vote.” This enhances the ability for smart contracts to work in situations where majority votes are needed, but the confidentiality of members needs to be preserved.