Abstract: Concerning of the security and efficiency problems of the agricultural product traceability system, based on the decentralization security feature of blockchain, an efficient solution based on consortium blockchain was proposed. Firstly, through Inter-Planetary File System (IPFS), the agricultural product data was hashed, so as to reduce the data size of single transactions in the block, and the initial guarantee of data was achieved by using the irreversible principle of IPFS data. Secondly, the consortium blockchain model for data verification was established, and Practical Byzantine Fault Tolerant (PBFT) algorithm was used as consensus algorithm for blockchain data verification to reduce the consensus time of the whole network. Finally, according to the number of participating nodes, block size and network bandwidth in the simulation experiment, the time curve of the verification transaction was fitted, and then the blockchain transaction efficiency under different bandwidths was calculated; by using tens of thousands of actual situations of the agricultural product traceability system with the participation of sensors, the blockchain double-chain structure was compared to obtain the analysis results. Experimental results show that under the condition of less than 1000 verification nodes, the maximum consensus time of blockchain is 32 min, and the consortium blockchain system can support 350000-400000 sensor data, which can be applied to large-scale and multi-data agricultural product traceability.

Key words: consortium blockchain, agricultural product traceability, Inter-Planetary File System (IPFS), Practical Byzantine Fault Tolerance (PBFT) algorithm, transaction efficiency

摘要： 针对农产品追溯系统中的安全和效率问题，依据区块链的去中心化安全特性，提出一种基于联盟区块链的高效解决办法。首先，通过星际文件系统（IPFS）对农产品数据进行hash转变，从而减小区块中单条事务数据量，并利用IPFS数据的不可逆原理，达到数据的初步保障；其次，建立联盟区块链模型进行数据验证，区块链数据验证的共识算法采用实用拜占庭容错（PBFT）算法来减少全网共识时间；最后，根据仿真实验中参与节点数、区块大小和网络带宽，来拟合验证交易的时间曲线，进而计算出不同带宽下的区块链交易效率，并结合数以万计的传感器参与下的农产品追溯系统的实际情况，对比区块链双链结构，给出分析结果。实验结果表明，在低于1000个验证节点的条件下，区块链最大共识时长为32 min，联盟链系统可支持35~40万条传感器数据，可适用于大范围、多数据的农产品追溯。

关键词: 联盟区块链, 农产品追溯, 星际文件系统, 实用拜占庭容错算法, 交易效率