Supply chain financial service platform based on blockchain
Ma Xiaofeng 1, Du Mingxiao 1, Yu Wenbing 2, Wang Yi 1
1 Department of control science and engineering, Tongji University , Shanghai 201804
2 Shanghai Ouye Financial Information Service Co., Ltd , Shanghai 201804
Abstract ： Blockchain has decentralization 、 Stable, secure and tamper proof features , With the further improvement and application of blockchain Technology , Blockchain will work with Finance 、 Medical care 、 Logistics and other traditional industries . This will overturn the existing mode of operation in some industries , Reconstruct a network of value transmission . We explored the application of blockchain in the field of supply chain finance , Build a supply chain financial service platform based on alliance blockchain . The platform combines blockchain technology with traditional systems , It provides a more convenient way of financing for all parties in the supply chain , Improve the transparency of the supply chain 、 Traceability and safety .
key word ： Blockchain ; Supply chain finance ; big data
Citation format of the paper ：
Ma Xiaofeng , Du Mingxiao , Yu Wenbing , Wang Yi . Supply chain financial service platform based on blockchain . big data [J], 2018, 4(1):13-21
MA X F, DU M X, YU W B, WANG Y. Blockchain based supply-chain finance service platform.Big Data Research[J], 2018, 4(1): 13-21
2008 year , Nakamoto first proposed the concept of blockchain , He takes the blockchain technology as the basic technology for building the basic data structure of bitcoin and encrypting and transmitting the data safely , A decentralized database for recording bitcoin transactions is realized . Blockchain has decentralization 、 Collective maintenance 、 Highly transparent 、 To trust 、 Anonymity, etc , It has been applied innovatively in the bitcoin system , It is also widely concerned by governments and enterprises all over the world , Many countries in the world have raised blockchain technology to a strategic height . Our country also in “ Much starker choices-and graver consequences-in ” Blockchain technology has been mentioned many times in the national informatization plan , It highlights the state's attention and attention to strategic frontier technology . Santander believes that , To 2020 If banks all over the world use blockchain Technology , Every year about 200 Billion dollars in costs . World Economic Forum （World Economic Forum） forecast , To 2027 Year world GDP Of 10% Will be stored on the blockchain network .
Bitcoin is also the first application of blockchain in the financial field , Blockchain is the underlying technology of bitcoin and other digital currencies , With decentralization 、 Stable and safe 、 It can't be tampered with , It has a good application prospect in building a trustworthy system . at present , The application of blockchain has extended to the financial industry 、 The Internet of things 、 Intelligent manufacturing 、 Digital asset trading 、 Property rights protection and other fields .
In the field of Supply Chain Finance , China is the world's leading producer and consumer of commodities , It's very important in global commodities . However, as the global economy enters a downward cycle , default 、 Loan fraud is frequent , The credit crisis of commodities is also emerging . Repeated pledge caused by asymmetric information of pledge 、 The occurrence of risk events such as empty order pledge , It has seriously damaged the mutual trust of all financing parties , It's hard to guarantee honest management , Warehouse supervision becomes a difficulty ; The financial order has been disrupted , The number of bad bank loans has risen , Financial institutions tend to reduce loans 、 Speed up the collection of loans ; meanwhile , The circulation of bulk goods is difficult , The capital chain of traders is tight 、 Loans are harder , Business development is in trouble .
Blockchain technology can effectively solve the problem of goods in storage 、 logistics 、 The problem of information asymmetry in supervision . Financing based on blockchain digital assets , It provides a convenient and effective way of financing for enterprises , It also expands the business scope for warehousing enterprises . The construction of digital asset system of blockchain supply chain can further promote the remodeling of commodity trading and financing credit system , Promote the normative development of the industry .
This paper uses blockchain technology to build a supply chain financial service platform , It is convenient for the core enterprises and financial institutions in the supply chain to jointly manage the information flow and capital flow of the upstream and downstream enterprises , Improve the transparency of supply chain finance 、 Traceability and safety , Solve the problem of information asymmetry in traditional supply chain finance , Lower the level of financial risk , Improve the overall efficiency of supply chain finance , Reduce the total cost of the supply chain , To provide better financial services for all parties involved in the supply chain .
2 Blockchain Technology
2.1 Blockchain and bitcoin
The paper published by Nakamoto describes his new idea of electronic currency , Design bitcoin based on the bottom of blockchain , It has solved the three difficulties that have plagued the development of e-money for a long time ： Repeat payment 、 Relying on third party centers 、 Circulation control . The core technologies of bitcoin are as follows ：
● Using peer-to-peer network technology to trade ;
● There is no need for financial institutions to participate in the transaction ;
● Use asymmetric encryption 、 Reusable proof of work （proof of work,POW） Instead of Central Trust ;
● Most of the nodes in the system are loyal , Together to maintain the longest chain ;
● Nodes can leave or rejoin the network , Receive changes in the longest chain and update the ledger .
In the above technology , Peer to peer network technology 、 Asymmetric encryption technology solves the problem of establishing distributed transaction books ; Reusable POW It's solved “ Double pay ” The problem of , Put an end to those who don't mean well through *** The phenomenon of unlimited repeated consumption of bitcoin by the central server . Besides , The number of bitcoins is limited to 2 100 m , Ensuring the scarcity of bitcoin .
Bitcoin in the form of a transaction is a string of characters , This string contains the information of the last transaction and the public key of the next owner （ Hereinafter referred to as public key ） Information , And send it to the payee （ The next owner ）. The payee will verify this string of characters , And broadcast it all over the Internet . The approved transaction information will be confirmed to form a block , The payee can use his private key （ Hereinafter referred to as private key ） Receiving bitcoin remittance , chart 1 For bitcoin trading .
chart 1 Bitcoin trading signals
2.2 Blockchain Technology
Pass on Unified trading needs a centralized trust institution , Confirmation of the transaction 、 Records depend entirely on the trust agency , In terms of transaction costs 、 There are many problems in efficiency and security . Blockchain technology has changed this situation , Blockchain has the characteristics of decentralization , The nodes participating in the blockchain have equal status , There is no need to trust each other between nodes , Through pre agreed rules , Reach a consensus on the principle of majority , To accomplish the distributed storage of data together 、 Confirmation of transaction information and other functions , Efficient 、 Low cost solution to the transaction problem between nodes . Blockchain contains peer-to-peer network technology 、 Asymmetric encryption 、 Consensus mechanism 、 Distributed ledger and other computer technologies , It is a comprehensive system of computer technology .
Peer to peer network technology is also known as peer-to-peer Internet technology or peer-to-peer technology , It is a networking technology for blockchain system to connect peer nodes , It is a kind of connection network built on the Internet corresponding to the centralized connection network . In Peer-to-Peer Networks , The computer nodes are equal , Nodes interact with each other through specific protocols , It is in sharp contrast to the centralized network service mode . Before bitcoin , Peer to peer network technology is mainly used for file sharing and downloading 、 Network video playing and so on . Peer to peer network technology is one of the core technologies of blockchain technology architecture .
Asymmetric encryption algorithm is a key based information encryption and decryption method , You need two keys ： Public key and private key . The public key and the private key are a pair . If you use the public key to encrypt the data , Only the corresponding private key can be used to decrypt . Because encryption and decryption use different keys , So this encryption algorithm is called asymmetric encryption algorithm . The public key can be published publicly , Used for sender to encrypt information to be sent , The private key is used by the receiver to decrypt the received encrypted content . The commonly used asymmetric encryption algorithms are R SA、ECC etc. . Blockchain uses asymmetric encrypted public-private key pairs to construct secure communication between nodes , Ensure the credibility and verifiability of the node . With the increasing demand for transaction privacy protection and the development of quantum computing , Based on zero knowledge proof 、 Homomorphic encryption 、 The privacy protection mechanism of ring signature and all kinds of quantum resistance based on lattice theory etc *** Our encryption methods are constantly being integrated into the blockchain .
Consensus mechanism is an algorithm for multi node consensus in blockchain , Blockchain uses consensus mechanism to jointly verify transactions to solve Solve the problem of double cost . In the blockchain system , Multiple nodes can communicate point to point , But some nodes will be malicious ***, The content of the communication has been tampered with . Normal nodes need to distinguish the tampered information , And the result is consistent with other normal nodes , Depending on the environment of the node , We need to design corresponding consensus algorithm . At present , Common consensus algorithms in the public chain are POW And proof of ownership （proof of stake,POS）, In the alliance chain , The main choice is practical Byzantine fault tolerance （practical Byzantine fault tolerance,P BFT） Algorithms or classes Paxos Algorithm （ Such as Raft Algorithm ）.
POW The algorithm is to allocate accounting rights and rewards among nodes through the competition of computing power . Different nodes compete to calculate the specific solution of a mathematical problem according to the information of the previous block , This mathematical problem is difficult to solve but easy to calculate , The node that first solves this mathematical problem can create the next block , And get a certain amount of bitcoin rewards .POS The algorithm is in POW The concept of currency age is added on the basis of , By changing the number of coins held 、 The combination of holding time and calculation difficulty , To some extent, it solved POW On the waste of resources in China .
In distributed systems , Byzantine fault tolerance technology can solve the problem of node and transmission errors , But early Byzantine systems required exponential complexity , until 1999 It was proposed that PBFT System , The complexity of the algorithm is reduced to polynomial level , Greatly improved efficiency . Worship in After the question of general zhanting was raised ,Lamport stay 1990 It was proposed that Paxos Algorithm , It is used to solve the consistency problem under specific premise , But because the content of the paper is difficult to understand, it is not accepted .1998 year Lamport Reprint the paper , And in 2001 Years of Paxos A brief introduction is given , And then Paxos Dominates the field of consistent algorithms , And many other algorithms are derived from it . but Paxos The algorithm is too theoretical , There are great difficulties in understanding and engineering implementation .2013 year , Stanford University Ongaro D And so on Raft Algorithm , Realized and Paxos The same effect , And it's easier to realize and understand .Raft The algorithm can't solve the Byzantine fault tolerance problem , But there are only downtime errors 、 In the absence of malicious nodes , It can complete synchronization between nodes faster , Throughput is also significantly better than PBFT Algorithm .
3 The application of blockchain in the field of supply chain finance
In recent years , The financing market for supply chain commodities is in dire straits . Take steel commodities as an example , The steel market is weak , Steel prices continue to fall , The price of steel trade is upside down , In the context of the development dilemma of the iron and steel industry , The severe financial pressure of iron and steel trading enterprises is increasingly turning into a real credit crisis .2012 year , There have been hundreds of repeated pledge in the field of domestic steel storage 、 Empty single pledge and other credit cases , The amount involved exceeds 100 billion yuan . This also leads to the destruction of the credit environment of the warehousing and logistics industry , Quality warehouses are not recognized , Warehouse management is deteriorating . There is an urgent need for effective solutions to resolve the crisis .
In the supply chain , More competitive 、 Large scale core enterprises are coordinating the information flow of supply chain 、 Logistics and capital flow play an irreplaceable role , It is this situation that causes the de facto inequality of supply chain members and information asymmetry .
Based on the above background , In traditional supply chain management 、 On the basis of financing platform , Build a supply chain financial service platform combining blockchain and big data analysis , The platform revolves around the core enterprise , By financial institutions and core enterprises to build , Can provide offline assets into electronic assets 、 Asset financing 、 Asset transactions 、 The function of asset bidding , Record user behavior , And big data analysis , Give reasonable user credit rating suggestions , Urge relevant participants to enhance their sense of integrity . Build a peer-to-peer trust mechanism with the help of blockchain technology , Build a comprehensive financing mode of dynamic credit enhancement assets .
The platform integrates the blockchain distributed ledger with the traditional centralized platform , Form a limited distributed hybrid architecture , It can take into account the internal control requirements of the centralized platform , Meet current regulatory requirements , It can also give full play to the typical features of blockchain distributed ledger , Complementary advantages . Using self-designed blockchain —— The Wutong chain is used as a chain platform for the underlying blocks , And use cross chain technology , Make business bookkeeping and account system run on different chains , Work together to complete the business process , But business accounting chain and digital asset circulation chain are isolated from each other .
3.1 Public chain and alliance chain
According to the degree of openness, blockchain can be divided into public chain and alliance chain . Public chain refers to the blockchain that all people in a public area can access . Everyone can be a node in it , And contribute according to the rules 、 Get a reward , There is no trust relationship between nodes . The public chain is completely open and decentralized , For completely open scenarios , At present, there are more mature applications .POW and POS Is the most commonly used consensus algorithm in the public chain .
Alliance chain refers to the multi-party participation and consensus node is the node pre designated by the participants . There is no complete trust between the participants in the alliance chain , Each party chooses its own consensus node according to the alliance rules , Transactions need to be confirmed by most consensus nodes . The joining of the nodes in the alliance chain needs to comply with the preset rules of the alliance chain , And only the node of the party has read permission , Opening up some of the authority to the outside world . The degree of openness and decentralization of alliance chain is weaker than that of public chain , But the transaction processing speed and waiting time are better than the public chain . Alliance chains are applied to semi closed networks , Such as the network built by different enterprises . In this kind of network , There may be a conflict of interest with the enterprise , There may be nodes that maliciously tamper with data .
The platform regards the core enterprises in the supply chain as relatively trustworthy institutions , The data interaction consensus of core nodes is carried out among several verification enterprises with high credibility , Therefore, the platform adopts alliance chain as the underlying networking form of blockchain . The initial joining of platform consensus nodes is selected by core enterprises , The joining of subsequent consensus nodes needs to be decided by the joint voting of existing consensus nodes .
3.2 Platform architecture design
The node of the platform initially participating in blockchain verification is set as the core enterprise 、 Logistics enterprises 、 Warehouses and banks , These enterprises are the core of the supply chain , And maintaining the stability of the system is more in line with the interests of the participating nodes , In the absence of external *** Under the circumstances , The data tampering of single node does not affect the stability and accuracy of the whole system . Other individuals or participating enterprises act as users of the system , Only participate in the business on the blockchain , Do not participate in consensus .
Considering that the current blockchain system is not suitable for storing large files , The data of platform blockchain is designed , Different services are encapsulated as functional modules , Each module interacts through the interface , And communicate with the outside , Each transaction module is based on the needs of business and privacy protection , Select the necessary key data , After using different encryption methods to encrypt data , Recorded on the blockchain . Pictured 2 Shown , The supply chain financial service platform based on blockchain consists of the underlying platform of blockchain and external service application layer , The application module includes privilege management module 、 Digital asset management module 、 Digital asset trading module and credit management module .
chart 2 Supply chain financial service platform architecture based on blockchain
The authority management module is responsible for the management of platform user authority , When users register on the platform , The authority management carries on the backstage audit to the user's information , And then give the system different permissions , For example, the administrator user can complete the approval of digital asset application . meanwhile , The authority management module will be combined with the credit scoring module , Reduce high risk 、 Users with low ratings have access to （ If you can't apply for digital assets 、 You can't trade digital assets, etc ）, And warning on the platform .
The digital asset management module is responsible for the approval of the user's application for registration of offline assets as online assets and the management of online digital assets after the approval . chart 3 It's a typical digital asset issuance process , Users confirm the offline physical assets application as online assets , Digital asset management module through the audit of physical assets , For example, the audit of bulk goods warehouse receipt needs to be connected with the warehouse system , The quantity of warehouse receipt items is calculated by the warehouse system 、 Quality and other information . The approved offline assets are frozen , And a qualified third-party organization will evaluate the value of the goods , Generate digital assets with offline asset details and valuation . The frozen logistics information will be monitored by the warehouse , The changes and handover of logistics are recorded on the blockchain in real time in the system , If it's not regulated , The system freezes digital assets . The digital asset application process and generated digital assets are recorded on the blockchain . The digital asset exit process is similar to the application process , After the digital asset management module is approved , Automatic payment of management fees through smart contracts , Unfreeze offline assets .
chart 3 Digital asset issuance process
Digital asset transaction module provides the function of digital asset transaction between users . Users can list the generated digital assets in the digital asset trading module , If other users meet the restrictions set by the seller （ Such as credit rating 、 User type, etc ）, You can buy digital assets in the transaction module , Transactions in digital assets are automatically executed through smart contracts , And record the transaction information on the blockchain .
Some companies can convert capacity into digital assets , And pre-sale on the platform , The pre-sale of production capacity is similar to that of an exchange , The trading module can split the traded products , And automatically match transactions . Enterprises can also finance digital assets , Through the pre-set smart contract template of the platform , Release digital assets to finance , And redeem the assets according to the agreed time limit . If the repayment cannot be completed on time , The smart contract completes the change of asset owner .
The credit management module is based on the user's behavior on the platform and the user's social credit , Comprehensive generation of users' credit records on the platform . The record is automatically generated by the analysis model , And recorded on the blockchain , When trading, the platform shows the credit situation to both parties , And according to the user's credit situation to provide different operation permissions .
3.3 Blockchain and big data
From a data point of view , Blockchain is a non tamperable 、 Full history database storage technology , The huge block data set contains every transaction in the past . With the rapid development of blockchain applications , The data scale will be bigger and bigger , The data fusion of blockchain in different business scenarios also further expands the data scale , Improved data richness . The growing maturity of big data technology also provides the possibility of financial risk control in the supply chain . The platform will record the user's behavior on the blockchain , By modeling and analyzing these data , Using non-financial data （ transaction 、 payment ） To provide financial institutions with the basis for enterprise credit evaluation , Give reasonable user credit rating suggestions , Urge relevant participants to enhance their sense of integrity , Build a platform for integrity .
chart 4 Technical route for platform credit service . The big data credit analysis module of the platform collects a large amount of enterprise business information , As the core data system of enterprise credit reference , And all kinds of governments 、 Business circles 、 Bank 、 Personal and other public information , By modeling , Establish enterprise credit reference system . With the accumulation and change of real business data , The platform can achieve dynamic tracking of enterprise credit , Release the latest credit situation of enterprises , Make the enterprise credit data embedded in the supply chain financial services .
chart 4 Platform credit service technology route
The supply chain financial service platform constructed in this paper is an attempt of blockchain technology in the field of commodity supply chain , The platform integrates blockchain technology and big data analysis , So that the original financing mode based on the guarantee assets is transformed into a comprehensive financing mode , Build a peer-to-peer trust mechanism , So that all enterprises in the supply chain can participate in it more equally . But there are still deficiencies in the current platform , For example, the throughput of consensus mode is limited 、 Unable to meet the needs of high frequency trading 、 The problem of privacy protection is not fully considered . In the future, the author will improve the consensus algorithm according to the actual running environment , Improve the throughput and confirmation delay of platform transactions ; Try to use zero knowledge proof and homomorphic encryption , Strengthen the privacy protection of participating users .
The authors have declared that no competing interests exist.
The author has declared that there is no competitive interest .