Efficient Three-Party ECDSA Signature Based on Replicated Secret Sharing With Identifiable Abort

Abstract

The private key is the only credential that can control and access account assets in the blockchain. Once the private key is leaked or stolen, the user loses control of the assets. The current mainstream solution is a threshold signature scheme based on secure multi-party computation, which can privately calculate the signature value without recovering the complete private key. However, most existing solutions are based on homomorphic or oblivious transmission, which have problems such as large computational or communication overhead and complex implementation. We designed a threshold signature scheme that relies only on zero-knowledge proofs and pseudo-random functions, and extended the identifiable abort mechanism to hold the corrupted party accountable afterwards. We implemented the new protocol based on the miracl library. The time cost for the key generation phase is 19.23ms, the communication cost is 96 bytes, and the signature phase is 21.41ms, the communication cost is 608 bytes. The overall time is about 81.61% faster than Lindell’18 and about 37.95% faster than DKLs’19.