Blockchain Technology & Transaction Application In Central Bank

At present, the overall process of central bank digital currency pursuing the convenience, speed, low cost, security and privacy protection of retail payment systems has been steadily advancing.

The blockchain technology with certain practical experience has the technical characteristics of peer-to-peer transaction, distributed accounting, block information broadcasting, etc., which can effectively improve the efficiency and economy of the transaction. It is undoubtedly a popular candidate for the central bank digital currency technology. .
However, the blockchain technology born out of the flat network essentially pursues the concept of free trading of data weaving. It has a certain degree of agreement with the central bank's demand for digital currency, and there are many differences, which need to be carefully considered and managed to be bridged.

Differences between blockchain technology and central bank digital currency demand
(1) Decentralization of the blockchain and the divergence of the top-level structure of the central bank's digital currency. The transaction information is reached as much as possible in the parallel node network to reach consensus and broadcast and spread, so as to promote the central responsibility of some or all network members, gradually blur or even replace the role of the transaction center, achieve homogenous nodes and balance the center of gravity, reduce the system The overall trust cost while enhancing the robustness and transparency of the data, this design concept is the decentralization of the blockchain.

The central bank's digital currency requires that while the transaction is optimized through new technologies, its essential attributes as the legal currency of the country cannot be shaken. Therefore, the central bank, as the basis for the existence of the national legal currency, the direct agency and actual execution department of the endorsement of state power, must adhere to the core position of key links such as currency deposit and management, monetary policy formulation and transmission, in the blockchain system. The highest authority and macro-control capabilities above other nodes should be enjoyed, which runs counter to the decentralized design of the blockchain.

(2) The differences between blockchain private key dependence and the universality of the central bank's digital currency audience. Asymmetric encryption system is the cryptographic basis of blockchain technology. With the HASH function independent variable and dependent variable incremental nonlinear correlation, with the RSA, DH, elliptic curve and other encryption problems, the important fact that the public and private keys cannot mutually resolve To achieve transaction security in a non-trusted open network environment. In this system, HASH plaintext, digital signature and public key are shared as public information for the whole network. Only the private key is the only rely on the holder of the transaction to claim ownership of the transaction information, and only the valid transaction area is encrypted and initiated by the private key. In order to get the consensus of the whole network, this determines that the blockchain transaction only recognizes the endogenous constraints of the private key and does not recognize the person; at the same time, because the effective transaction block attached to the end of the blockchain has been completed in the consensus circle of the whole network. Distributed accounting, so it is very difficult to carry out unified rollback and correction, which leads to the loss, theft and abuse of the private key. The blockchain itself is difficult to confirm the consequences, and can not make up for the loss.

In summary, blockchain technology has deep-rooted dependence on private keys. The holders of the central bank's digital currency are ordinary people who have different ability to accept new things. They need to use the legal currency with a lower threshold, especially the legal currency that can accommodate their negligence and can quickly respond to and recover damages. The unique location of private keys in the blockchain will be a heavy burden for their convenient and secure use.

c) The differences between the blockchain transaction information and the central bank's digital currency confidentiality requirements. The blockchain technique replaces the node's respective balance records with the sole transaction record of the main chain to make the transaction feasibility judgment. When the transaction occurs, the consensus circle backtracks the relevant transaction records of the main chain, summarizes the roll and judges the rationality, which is the basic consensus mechanism of the blockchain technology distributed database, which means the holographic information of the token products to the consensus circle. Members are known. This is a very important positive for the central bank's digital currency, and it is also a hidden danger that needs to be handled with caution.

On the basis of the central bank's digital currency research, the central bank can use the big data analysis technology to detect economic individual behavior, grasp the macro from the micro, improve the efficiency of macro-prudential supervision, and effectively prevent the financial system. Sexual risk; the hidden danger is that the blockchain mechanism requires that this part of the information must be contacted by all the nodes of the consensus circle rather than the central bank, further considering that the central bank digital currency will inevitably require the user's address real name authentication, then this part of the information It is not only a micro-account of national economic activities for a period of time, but also a detailed account of the personal payment and payment behavior of the holders. It has very important political, economic and social significance. Once the leaks mean not only the key data of the national economic operation dynamics are exposed. It is more likely to trigger the sensitivity and concern of the majority of the holders of personal privacy exposure. The central bank must ensure that members of the consensus circle, including themselves, are safely stored, reasonably applied, and strictly confidential.

Feasible suggestions for dealing with differences

(1) Constructing a two-circle system of alliance chains that are separated and coordinated. The alliance chain double circle system is based on the BFT consensus. It is a blockchain form with a small number of top-level nodes but strict hierarchical control rights. It can support a highly contracted consensus circle with a wide expansion of trading circles, and central bank figures. The dualistic needs of money are in line.
The consensus circle in the double-circle system consists of the central bank and commercial banks. All blockchain transactions require the relevant authority members of this layer to confirm, broadcast and write to the main chain. The central bank is at the core of the consensus circle, fulfilling the functions of member control, data maintenance, and process management, maintaining a smooth and orderly operation of the main chain, participating in the consensus of each transaction data, and independently owning the highest reading of all blocks in the main chain. Write permission. Commercial banks are responsible for transactions within their own authority and work with the central bank to maintain effective data on the main chain. In addition to the functions in the blockchain system, the original currency-related functions of the central bank and commercial banks are still maintained.

The trading circle of the double-circle system is fully engaged in the transaction by the central bank digital currency holder who does not have any data writing authority at the address-to-address level by the steps of initiating or responding to the transaction information, receiving the transaction result, and performing the actual delivery. The consensus circle is responsible for completing and feedback.

The double-loop system of the alliance chain adopts the two-layer design of the consensus circle and the trading circle to realize the separation and cooperation of transaction response and confirmation. The consensus circle of strong control has defended the central position of the central bank's currency, while the trading circle that fully reflects the technological advantages of the blockchain has realized the convenience, speed and low cost of the central bank's digital currency for retail transactions.

(2) The commercial bank accepts the entrustment to become the actual executor of the transaction. On the basis of the double circle system, the willingness to separate transactions and actual operations can be further considered. The transaction initiator entrusts the transaction information containing the input, output and amount to the commercial bank. The entrusted bank manages the identity, address and private key of the Bank's entrusted client and converts the transaction information into a blockchain format after real-time backup with the central bank. And then use the corresponding private key of the transaction initiator to encrypt and package and send it to the central bank; the central bank performs address mapping according to the information content and distributes the transaction information to the trusted bank of the counterparty; the digital signature of the bank processed by the HASH processed plaintext and public key The comparison, the backtracking and roll-off of the transaction information of the main chain, the check of the validity of the transaction, etc., complete the confirmation of the transaction and feedback to the central bank; after confirming the correctness, the central bank broadcasts the result to the members of the consensus circle and conducts distributed accounting with the corresponding authorized members. The transaction process is completed.
This system transforms the retail customer's peer-to-peer transaction into an address-to-address transaction managed by the commercial bank, which essentially transforms the direct risk entity from the ordinary people into a commercial bank with stronger execution and pressure resistance and more convenient central bank management. , greatly enhanced the risk control of the private key in actual use, effectively ensuring smooth trading of the majority of the holders.
(3) Multi-pronged technical means to prevent leakage of core data. In order to ensure the security of data, we should first strengthen the technical reserve for the concurrent processing, queue strategy, data stack, depth search and delay suspension of extremely high pressure peaks, and consolidate the system technology framework. Secondly, members of the consensus circle (ie commercial banks) who have the necessary information to obtain historical transaction information should further adopt multi-dimensional and strict technical means to limit their additional exploration and record of core data: including but not limited to serious authority management, to ensure that commercial banks only It can process transaction data, execute transaction operations, manage transaction content, maintain transaction network within the scope of its own node permissions; strengthen backtracking control, ensure that commercial banks only perform automatic backtracking and temporary storage of transaction records in the necessary verification links of transactions. And the result is automatically forcibly cleared after the end of the process, absolutely prohibiting any form of manual backtracking; limiting the consensus operation to ensure that commercial banks only add valid trading blocks at the end of the main chain when reaching consensus, and cannot use the open trading exposure at this time. Explore the main chain content in the direction of the reverse data stream.