An Efficient Blockchain Consensus Algorithm Based on Post-Quantum Threshold Signature

Abstract Blockchain is a distributed and append-only data management system maintained by many nodes from Peer-to-Peer (P2P) networks, where one of the most important and successful applications is Bitcoin. In blockchain P 2 P networks, consensus algorithms are playing a key role and take a lot of time. For example, Bitcoin uses Proof-of-Work (PoW) consensus algorithm, which takes 60 minutes to acknowledge a new transaction. Compared with the traditional data management technology, blockchain systems are very inefficient. Thus, it is very crucial to improve the blockchain consensus. We present threshold digital signature techniques to exploit the blockchain consensus mechanism. First, we propose a threshold signature scheme based on NP-hard problem, i.e., solving quadratic equations in a finite field, which is considered to be secure against quantum computer attacks and traditional attacks. Second, we further propose an efficient blockchain consensus algorithm based on the new threshold signature scheme. Third, we build a new blockchain system based on the consensus algorithm. The analysis of the blockchain system shows that the efficiency and security is must better than current blockchain systems.