面向食品溯源场景的PBFT优化算法应用研究

Application Research of PBFT Optimization Algorithm for Food Traceability Scenarios

区块链不可篡改、可追溯等特性能较好地支撑食品溯源系统,在食品溯源与区块链技术相结合的应用中存在着延时长、节点多、系统开销大等问题。针对上述问题,基于实用拜占庭容错算法(Practical Byzantine Fault Tolerance,PBFT),提出一种适用于食品溯源场景的优化PBFT算法trace-PBFT(t-PBFT)。首先,将供应链中节点划分为3个等级,根据节点在共识中的实际通信量动态更新节点状态,并以此来评价节点的可靠性,作为选举主节点的依据;其次,结合食品供应链的特点,优化原算法中的一致性协议,减少节点通信次数。实验结果表明,相比PBFT算法,t-PBFT算法在通信开销、请求延时、吞吐量等方面表现更优;最后,基于t-PBFT算法且结合联盟链提出一种满足食品溯源需求的架构模型,对食品供应链中各环节进行数据记录,保证数据可追溯,确保食品流通过程的安全性。

The characteristics of blockchain such as immutability and traceability can better support the food traceability system,and there are problems such as long delay,many nodes and high system overhead in the application of food traceability combined with blockchain technology.To address the above problems,an optimized PBFT algorithm trace-PBFT(t-PBFT)is proposed for the food traceability scenario based on the practical Byzantine fault tolerance(PBFT)algorithm.Firstly,the nodes in the supply chain are divided into three classes,and the node status is dynamically updated according to the actual communication volume of the nodes in the consensus,which is used to evaluate the reliability of the nodes as the basis for electing the master node.Secon-dly,the consistency protocol in the original algorithm is optimized to reduce the number of node communications by combining the characteristics of the food supply chain.Experimental results show that the t-PBFT algorithm performs better than the PBFT algorithm in terms of communication overhead,request delay and throughput.Finally,based on the t-PBFT algorithm and combined with the consortium chain,an architectural model to meet the demand of food traceability is proposed.It can record the data of each link in the food supply chain,ensure data traceability and the safety of food circulation process.