Decentralized Blockchain Transaction Scheme Based on Digital Commitment

Abstract

As a framework based on data transaction between blocks, blockchain has a high degree of transparency and decentralization. Zhang et al. proposed a transaction framework that combines digital commitment and cryptographic algorithm, which can hide the transaction amount during transaction process. However, there are two problems we should consider: the transactions recording on ledger are operated by trusted full-functional accounting nodes, so the decentralization of the blockchain cannot be realized completely; there is also a risk of data leakage during transaction process as the transaction parameters and transaction amounts are required to be transmitted multiple times. In order to solve the above problems, this paper proposes a multi-key homomorphic encryption transaction scheme based on digital commitment with every node records transaction data. The transaction amount hidden in the commitment can be directly updated in the encrypted state and relevant parameters do not need to be transported multiple times. The transaction scheme proposed in this paper is with better efficiency and provable security, which provides a novel idea for the secure transaction framework in the blockchain.