Research On RFID Anti-collision Algorithm And Blockchain In Food Traceability Application

In recent years,food safety issues have attracted more and more attention from the society,and food traceability is an effective method to solve this problem.However,there are following problems in the food traceability system: 1)Data acquisition.RFID data acquisition technology is increasingly popular,but tag collision has become the main problem affecting the efficiency of RFID identification.RFID anti-collision algorithm is the main method to solve this problem,but most of the mainstream anti-collision algorithms are based on the stationary environment where tags are static,which are difficult to satisfy the actual data acquisition applications in food moving scene(such as food is identified in the port logistics,warehouse and other scenarios),and presents high tag misreading rate and low identification efficiency.2)Data storage traceability.The traditional method mainly conducts centralized or distributed storage of collected food information in a centralized database,which not only easily leads to data tampering and information disclosure,but also makes centralized storage vulnerable to single node attack and system collapse.Blockchain offers solutions to these problems with its new decentralized architecture,distributed ledger technology,and ability to prevent data tampering.However,blockchain technology also has some problems to be solved,such as data explosion and sensitive information disclosure.In order to solve the above problems,this thesis studies the application of RFID anti-collision algorithm and blockchain technology in food traceability respectively.The main contributions are list as following:(1)A RFID anti-collision algorithm for tag moving scene is proposed.Firstly,a tag distinguishing mechanism is proposed,through which the arriving tags and staying tags can be accurately distinguished;Then,a method for estimating the number of tags is proposed,by which the number of arriving tags and staying tags can be accurately estimated.Finally,a hybrid tag identification strategy is proposed,which is based on the estimated number of tags to identify tags.(2)A collaborative storage traceability model of on-chain and off-chain is proposed.The model is divided into two modules: on-chain module and off-chain module.The on-chain module is a blockchain network connected by multiple blockchains,and the nodes are divided into RFID acquisition nodes、data processing nodes、block verification and storage nodes according to their roles and functions;The off-chain module consists of distributed database and distributed file system.The off-chain module is responsible for storing the food information collected by RFID,while the on-chain module stores the hash value of the food information collected by RFID,and they are correlated and corresponding through the unique on-chain and off-chain value.In this way,it not only guarantees the reliability and tamper-proof of data,but also avoids the data explosion of blockchain and the disclosure of sensitive information.Experimental development and test results show that the proposed algorithm and model have better performance than the compared algorithms and the mainstream storage traceability methods.