一种基于双链的区块链共识机制

A Dual-Chain-Based Consensus Mechanism for Blockchain

共识机制是区块链系统的核心技术,目前针对“非币”区块链系统提出的基于贡献值证明与工作量证明(Po C+Po W)的共识机制存在共识效率较低、可靠性和安全性不高、算力消耗大的缺点。提出一种新的基于双链的共识机制CON_DC_PBFT。在该共识机制中设计一种业务链-系统链双链结构,将贡献值等系统数据和主要业务数据分离到双链中各自完成共识处理,双链的共识表现为半独立的形式,业务链共识消息流受系统链监督协调,并且系统链根据贡献值随机指定业务链的记账节点,双链的分工与协同实现并行化和流水化,改善共识的效率。由于贡献值数据不能被轻易获取,通过拜占庭通信机制和节点随机选择算法,降低节点遭受攻击和系统停滞的风险。通过实验综合分析出块选择概率、单点故障率、节点数、区块传输速率、CPU使用率对共识机制的性能影响,结果表明,与Po C+Po W机制相比,CON_DC_PBFT共识机制节省了50%以上内存、存储资源占用,在综合共识时延上有30%以上的改善。

Consensus mechanism is the core technology of blockchain systems.Currently,a new consensus mechanism based on Proof of Contribution value and Proof of Work(PoC+PoW)has been proposed for″non-coin″blockchain systems.However,it presents some problems such as low efficiency,low reliability and security,and high computing-power consumption.Hence,this study proposes a new Consensus mechanism based on a Dual-Chain-PBFT(Con_DC_PBFT).In this mechanism,a dual-chain structure is designed to separate the contribution value and main business information for independent consensus processing.The consensus of the dual chain is of a semi-independent form,where the main-chain consensus message flow is supervised and coordinated by the subchain,and the subchain randomly designates the main-chain accounting nodes based on the contribution value.The division of labor and cooperation between the dual chains enables parallelization and pipeline processing,thus improving the efficiency of consensus.Moreover,the contribution value cannot be easily obtained,and the risks of node attacks and system stagnation are further reduced by adopting a Byzantine communication mechanism and a random-node-selection algorithm.A comprehensive experimental analysis pertaining to the effects of block-selection probability,single-point failure rate,number of nodes,block transmission rate,and CPU usage on the performance of the consensus mechanism shows that the Con_DC_PBFT consensus mechanism conserves more than 50%of memory and storage resources compared with PoC+PoW,as well as improves the overall consensus time delay by more than 30%.