Consortium blockchain private key protection scheme based on rational secret sharing and blockchain

Abstract

In a consortium blockchain, the loss of a private key can result in significant losses for users, making the protection of private keys particularly crucial. Traditional distributed private key protection methods are susceptible to threats such as node silence and collusion, leading to the inability to reconstruct the private key smoothly. To address this issue, this paper proposes a private key protection scheme based on rational secret sharing and blockchain. Users act as secret distributors, distributing secrets to nodes on the blockchain through secret sharing. When users need to use the private key, nodes share sub-keys. To incentivize nodes to actively respond to user requests, an incentive-compatible evolutionary game model is constructed. Dynamic incentive strategies are then adjusted through smart contracts to ensure that nodes honestly share sub-keys to reconstruct the user’s private key. This proposed scheme is the first to introduce evolutionary game theory into secret sharing to address issues of node silence or non-responsiveness. Through scheme analysis, it is found that the proposed scheme exhibits good performance in terms of correctness, security, and fairness.