Blockchain-based Rice Supply Chain Traceability to Ensure Rice quality and food safety

Rice is the grain feeds more than half of the world population. It is an important staple 1 food provides twenty percent of the calories consumed worldwide. Food safety affects the health 2 of consumers. Establishing an effective traceability system is one of the primary measures to 3 protect rice quality and food safety. Blockchain-based traceability system has the characteristics of 4 data tamper-proofing, decentralization, and co-governance. This paper proposed a rice traceability 5 scheme based on blockchain technology that selects the critical nodes in the rice industry chain 6 to construct a blockchain network to achieve transparent data sharing. It is meaningful for both 7 enterprises and consumers. It can let enterprises get the real quality information of rice and related 8 raw materials. Consumers can get the true information of rice and rice products to buy safe and 9 healthy food. The scheme is proved feasible by simulating the traceability of the rice supply chain. 10


Introduction
Rice is the grain that feeds more than half of the world population. A lot of rice 13 varieties of different species exist with yields ranging from 1-3 t/ha to 5 t/ha [1]. In the 14 process of selecting better cultivars, a special role is also played by the use of radiation- 15 induced mutations. In recent years, with the exposure of poisoned rice, golden rice, 16 and cadmium rice and frequent other rice problems seriously harmed the consumer's 17 health and has affected market order stability. It is a challenge to distinguish rice quality 18 from traditional methods, leading to a severe market phenomenon "Bad money drives 19 out good." Therefore, society is getting more and more concerned about rice quality 20 and food safety. The demand for the authenticity of the information on rice source and 21 production process is also increasing rapidly. 22 The rice quality traceability system provides an effective solution to protect rice 23 quality and safety. It conduces the rice industry structure's optimization and selects the 24 characteristic information related to the traceability target. It determines the stability 25 and reliability of the traceability information [2]. Over the years, researchers have made 26 many significant contributions to the field of food traceability. These achievements also 27 include the following significant methods. The near-infrared spectroscopy [3] but the 28 limitations of technology, modeling methods, and algorithms made it challenging to 29 popularize and applicable. The Isotope labeling traceability is good, but the cost is 30 high, and the efficiency is low [4]. DNA traceability [5][6] process of food processing 31 usually leads to the degradation and fragmentation of DNA. However, it would affect 32 identification and traceability. The Internet of things label traceability methods gained 33 popularity in the market due to the characteristics of efficiency and convenience [7]. will experience significant benefits. It will lead to research on optimizing the industry 42 chain and improving food traceability and anti-counterfeit. The blockchain technology 43 can build a trusted way with different organizations to support data sharing and ensure 44 the data reliability [8]. It is meaningful for all participants in the rice supply chain, as 45 follows.

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• It allows consumers to obtain the true information of the product to buy healthy 47 food [9,10].

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• The data sharing in rice industry enables enterprises and farms to understand the 49 real demand for their products in different region of the market, which is helpful to 50 effectively avoid food waste and economic lost due to goods excess inventory [11].

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• The existing market supervision system is not intelligent enough, and the govern- guarantee the data's reliability in the system [8].

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The rest of this paper is as follows: Section 2 introduces the blockchain technology 77 and the traceability system in rice supply chain. Section 3 introduces construction of a 78 rice traceability scheme. Section 4 describes the rice traceability system implementation.

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The conclusion is in section 5.  Blockchain technology has some advantage characteristics of decentralization, 86 tamper-proof, co-governance, and anonymity [21]. It can avoid data being corrupted 87 by internal administrators and external hackers among the processes such as storage, 88 transmission, and display, with blockchain features of decentralization and tamper-proof.

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The characteristics of co-governance and consensus enabled any participants to trust 90 the system's data, facilitating the popularity of system application. The anonymity 91 in blockchain technology would protect consumers' privacy where any user privacy 92 information was stored anonymously [22]. When quality and safety accidents occur, can satisfy multi-scene applications and have several advantages as follows.

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• Better performance than the public blockchain.

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• It supports the identity certificate service, which can provide higher security and 116 better controllability.

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• It not only meets the needs of the food industry but also fulfills the regulatory 118 requirements of the management agencies for rice quality safety.  support traceability and tracking [24]. In order to construct a rice traceability system, 129 the process should include the following steps.

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• Analyze the structure of the rice industry chain and record the information of 131 logistics and information flow processes.

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• Study the essential natural fingerprint information used for rice traceability.

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• Select feature information associated with the traceability target.

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• Ensure the stability and reliability of traceability information.

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Combined with the previous analysis of the key nodes in the food supply chain [8],  supply chain to collect data.

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The system service layer functions include P2P network construction that provides 161 a solution to communicate among node servers of physical layer. The consensus function 162 is used to ensure the consistency of each new data block in each node servers. Smart 163 contracts are used to build digital contracts based on business contracts.

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The system interface layer encapsulates service layer functions into standard web 165 API interfaces, supporting external application access with business requirements.      The system server configuration information, as described in Table 1 service information's tag information to achieve complex data-level logic processing.

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The system simulates the collection, display, and traceability of information for the 220 cultivation, warehousing, processing, and sales of the rice industry.   229 We proposed and implemented a supply chain traceability system based on blockchain 230 technology. The system inherits characteristics such as tamper-proofing, decentralization 231 and transparancy from blockchain technology. Our supply chain traceability system 232 provides transparent and tamper-proof data through out the supply chain at every pro-233 duction step. It improves the product quality as well as data quality to compete into the 234 consumer oriented market. The quality data can be used to assess the future production 235 and quality control management. It will also promotes the healthy competion between 236 the food producers to increase the product qualtiy to gain consumer trust and market 237 share.

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Recently, the system has realized the whole rice supply chain data sharing, but the 239 ability of mining data value still needs to be improved. So, the further work is to establish