Definition of traceability
Traceability refers to the sharing of information on agricultural products, industrial products and other commodities from production, processing, sales to consumer terminals, so as to serve the final consumers. In the case of the coverage of the whole process of traceability system, once a problem occurs, traceability system can quickly respond to the problem, obtain the information of the whole process of production and circulation of the problem products, and conduct investigation and positioning to determine the root cause of the problem, and then solve the problem pertinently.
Current situation of traceability industry
Since the 1990s, European and American countries began to carry out traceability construction. At present, a certain scale has been formed in food supervision, legislation and traceability construction. China's food and agricultural products traceability system construction is still in its infancy, the relevant legal basis, regulatory system, traceability standards, traceability information platform and so on are not yet perfect.
China's traceability industry is at the primary stage of construction, and there are problems of trust deficiency and abuse in the traceability industry. Because of information asymmetry, stakeholders change the data on the traceability chain at a very low cost and a low probability of disclosure. The emergence of block chain technology provides a solution for the lack of trust in the traceability industry.
Block Chain Helps Traceability Development
The growing demand for traceability of commodities has prompted the development of traceability industry. Block chain, as a new technology, provides a new way for traceability. Many enterprises seize the opportunity to enter the block chain market. According to incomplete statistics, since the beginning of 2018, more than five white papers on traceability projects of block chains have been published by relevant companies.
Block chain traceability enterprises are mainly divided into two categories. One is the new block chain startup company. The new industry and business model brought about by block chain technology has spawned a large number of start-up companies, who first step into the traceability market and seize market share.
The other is the Internet giants, who try to integrate block chain technology with their traditional industries to solve the practical problems of enterprises, while developing to a platform and providing multi-industry services.
Block Chain Traceability Model
Block chain traceability refers to the use of block chain technology, through its unique and non-tampering characteristics of distributed accounting records combined with Internet of Things and other technologies, to achieve commodities from the source of information collection and recording, traceability of raw materials, production process, processing links, warehousing information, inspection batches, logistics turnover to the third party. The whole process of quality inspection, customs entry and exit, anti-counterfeiting certification can be traced back.
Block chains use time stamps, consensus mechanisms and other technical means to achieve data can not be tampered with and traceable functions, providing technical support for the establishment of cross-agency traceability system. At the same time, the third-party supervision agencies and consumers are included in the supervision system, which breaks the information island, provides information support and achieves the transparency of production process to a certain extent. According to the different types of block chain, block chain traceability can be divided into public chain traceability, alliance chain traceability and private chain traceability.
The core technology of block chain traceability mainly includes the following three points.
(1) Block + Chain to achieve data traceability and not tamper with
In block chain technology, data is stored permanently in the form of electronic records and generated in chronological order. These electronic records are called blocks. Block chain is the combination of blocks in a chain way. The database formed in this way is called block chain database.
Block structure has two very important characteristics. First, transactions recorded on each block are all value exchange activities that occurred after the formation of the previous block and before the block was created, which ensures the integrity of the database. Second, in most cases, once the new block is completed, it is added to the block. Chain, then the data records of this block can no longer be changed or deleted, which ensures the rigor and authenticity of the database, that is, can not be tampered with.
Block chains provide the function of searching every data in the database. Each transaction data on the block chain can be traced back to its origin through the structure of the block chain and verified one by one. Block + Chain = timestamp, which is the biggest innovation of block chain database. Block chain database allows the whole network's loggers to stamp a time stamp in each block to account, indicating that this information is written at this time, forming a database that can not be tampered with and forged.
2) Distributed structure, decentralization and multi-party supervision of information
Nowadays, in the centralized system, data are centralized recorded and stored on the central computer. The central node has the possibility of tampering with data and forging. However, the block chain structure design ensures the authenticity of stored data supervised by many parties and linked information by constructing a set of protocol mechanism, which stores data on every node involved in data transaction and records the results and verifies them.
(3) Asymmetric encryption algorithm ensures the security of information on the chain.
In block chain system, the basis of ownership verification mechanism is asymmetric encryption algorithm. Asymmetric key, also known as public key encryption, encodes information with two mathematically related keys.
In this system, one of the keys is called public key, which can be sent to the person who wants to communicate securely with the key holder at will. Public keys are used to encrypt information. The second key is the private key, which belongs to the key holder. The holder needs to keep the private key carefully. The key holder decrypts the received information with the private key.
The party transmitting the information can be used to encrypt the plaintext, and the ciphertext can only be carried out by the private key.