CN107230071B

CN107230071B - Method and system for exchanging digital currency into physical cash

Info

Publication number: CN107230071B
Application number: CN201610179406.XA
Authority: CN
Inventors: 姚前; 李会锋; 温信祥; 李连三; 王栋兵; 刘浩; 赵欣; 唐晓雪; 刘文舒
Original assignee: Digital Currency Institute of the Peoples Bank of China
Current assignee: Digital Currency Institute of the Peoples Bank of China
Priority date: 2016-03-25
Filing date: 2016-03-25
Publication date: 2021-07-06
Anticipated expiration: 2036-03-25
Also published as: CN107230071A

Abstract

The invention provides a method and a system for converting digital currency into physical cash, which aim to solve various defects in the prior art. The method of the invention comprises the following steps: the user terminal equipment selects equivalent digital currency in the digital currency wallet according to the cash amount input by external operation; the user terminal equipment sends the digital currency to a central bank digital currency system through a commercial bank digital currency system; the central bank digital currency system generates a one-time withdrawal code and then sends the one-time withdrawal code to the user terminal equipment to be presented to the user, and owner information of the digital currency is changed into a central bank by the user; the commercial bank digital currency system sends the one-time withdrawal code provided by the user to the central bank digital currency system; the central bank digital currency system confirms that the one-time withdrawal code is valid, then adds the cash exchange amount to the commercial bank account, and feeds back the cash exchange amount to the commercial bank digital currency system; the commercial bank digital currency system issues a supply instruction based on the feedback.

Description

Method and system for exchanging digital currency into physical cash

Technical Field

The invention relates to the technical field of computer networks and computer software, in particular to a method and a system for converting digital currency into physical cash.

Background

Digital currency is currency that converts cash values into a series of electronically encrypted serial numbers, and the security of the currency itself relies on cryptographic algorithms to protect it. In the aspect of cryptographic algorithm, the security of the digital currency system relates to symmetric cipher, asymmetric cipher, message digest algorithm and identity-based cryptographic system, and the overall security of the cryptographic system, the selection of cryptographic algorithm, the implementation of cryptographic algorithm, the design of interactive protocol, the compatibility of international and domestic standards, etc. must be deeply considered in the aspect of system implementation to ensure the transaction security of the digital currency.

With the development and popularization of the mobile internet, the mobile payment industry is rapidly changed and promoted, business modes based on various technologies such as the mobile internet, NFC, HCE, Token, biological recognition and the like are continuously innovated, application scenes are continuously expanded and enriched, and the integrated development of online and offline businesses is accelerated. The new mobile payment technology provides diversified and convenient payment services for users, and leads the transformation, upgrading and development of industries such as communication, finance, internet and the like. The wide development prospect of mobile payment has become a wide consensus of the whole industry, and the mobile payment is considered to be an important cut-in point on a connecting line. The transaction system of digital currency should be designed with mobile payment as the core for business model.

In mobile payment business mode, the key storage carrier for digital currency can be provided by hardware SE modules (security modules), HCEs and TEEs. The hardware SE is widely applied to the prior debit and credit cards and electronic cash because the safe computing environment provided by the hardware SE is approved by the field of financial transactions, and has wide user foundation, good acceptance environment and use habit. With the continuous development of mobile payment technology, the form of the SE module is changed, and new solutions are practiced.

On a data transmission channel between a transaction acceptance terminal (POS machine) and a payment instrument (such as between a card and a mobile phone), there are currently a plurality of transmission modes: RF radio frequency communication, text messaging, code scanning, sound waves, photons, coexistence of multiple modes provides convenience for communication between payment carriers.

The authentication method can be classified into password-based authentication, password + smart card-based authentication, and biometric feature (fingerprint, face) based authentication. The password and the biometric authentication are mostly used for far-field payment, and the smart card authentication is mostly used for near-field payment.

Cloud computing is the mainstream direction of a background server side in the future, and a background system of digital currency should adopt a cloud-based solution.

In electronic commerce, the requirements for digital currency are different due to different roles: customers require digital currency to be convenient to use, safe to store and anonymous; the merchant requires the digital currency to be certifiable and to be exchanged into real currency; the bank requires that the digital money cannot be illegally used and forged, and thus, the digital money D-RMB should have the following characteristics:

1. safety: can prevent any party in the business from changing or illegally using the digital currency;

2. non-repeatable expense: the digital currency can be used only once, and the repeated cost can be easily checked;

3. controllable anonymity: the bank and the merchant are mutually hooked and cannot track the use of the digital currency, and the system cannot be required to link the purchasing behaviors of users of electronic cash together, so that the purchasing history of the users of the digital currency is concealed, but the issuer of the digital currency can track the use of the digital currency;

4. non-forgeability: digital currency that the user cannot counterfeit;

5. fairness: the payment process is fair, so that the transaction of both parties is successful or no loss is generated between both parties, and a certain transaction party is prevented from being damaged in the transaction;

6. compatibility: the issuing process and circulation link of digital currency in the D-RMB system refer to the issuing and circulation of physical currency as much as possible.

And for digital currency, the currency can be adapted to various use scenes of the existing currency and can be freely exchanged with the existing currency.

In real life, the two parties to the transaction do not always effect the transfer of funds in the form of physical cash. For example, company A may purchase a batch of instruments from company B, and pay twenty-ten-thousand dollars, and company A may give company B a twenty-ten-thousand dollar check, and let company B exchange the check for physical cash at bank. In addition to checks, notes such as deposit slips, promissory notes, and money orders are also common in which cash can be exchanged.

The deposit receipt is called deposit receipt for short, and the deposit receipt is also called deposit receipt which is a deposit certificate issued to a depositor by a bank. The deposit list can be divided into a periodical deposit list, a deposit list for taking out the deposit book, a deposit list for living and living, and the like. The fixed-length deposit receipt is a deposit which is taken when the deposit is in a contracted date and is due. It is suitable for saving the rest of living hinge and is used as a reserve for a certain period of time in the future.

The draft is a bill issued by a drawer and requires a payer to unconditionally pay a certain amount of money to a payee or a ticket holder when the payer sees the bill or within a certain period. Money orders are one of the most widely used credit instruments in international settlement.

Checks are promissory drafts with banks as payers, and may be considered a special case of drafts. The opening of a check deposit account and the receipt of a check must be credited reliably and at a certain amount of funds. The check can be classified into cash check, transfer check, and general check. The cheques can be circulated and transferred after being endorsed, have the function of currency and become a credit circulation tool which can play the roles of circulation means and payment means instead of currency. The check is used for currency settlement, so that the currency circulation amount can be reduced, and the currency circulation cost is saved. The prompted payment period for the check is 10 days from the date of drawing the ticket.

The ticket is a written promissory book which is issued to the drawee by the drawer, i.e. a certain amount of money is paid unconditionally or on a regular basis. The promissory note issued by the enterprise is generally called a promissory note, and the promissory note issued by the bank is called a bank promissory note. The bank note is issued by a bank institution, can be used for transferring money, and can be used for paying cash by noting cash.

The bill which can be exchanged for cash is usually in a paper form, and is easy to lose, steal, forge and the like. The bills need to be exchanged into cash manually by bank staff at a bank counter and cannot be finished by self, so that the time and energy of a bill holder are consumed. When in exchange, the user needs to exchange the card at one time and cannot be flexibly disassembled. Some of the tickets also have a certain period of time and are inconvenient to use.

Disclosure of Invention

In view of the above, the present invention provides a method and system for exchanging digital currency into physical cash, so as to solve the various deficiencies in the prior art. Other objects, effects, and advantages of the present invention can be derived from the embodiments.

The invention provides a method for exchanging digital currency into physical currency in a first aspect, which comprises the following steps: the user terminal equipment selects equivalent digital currency in the digital currency wallet according to the cash amount input by external operation; the user terminal device sends the digital currency to a commercial bank digital currency system; the commercial bank digital currency system sending the digital currency to a central bank digital currency system; the central bank digital currency system generates a one-time withdrawal code and then sends the one-time withdrawal code to the user terminal equipment to be presented to a user, and owner information of the digital currency is changed into a central bank by the user; the commercial bank digital currency system sending the one-time withdrawal code provided by the user to the central bank digital currency system; said central bank digital currency system confirming that said one-time withdrawal code is valid, then incrementing a commercial bank account by said cash redemption amount, and sending a notification to said commercial bank digital currency system that said one-time withdrawal code is valid; and the commercial bank digital currency system sends a money supply instruction after receiving the notification, wherein the money supply instruction is used for controlling a machine or prompting a manual cash supply user to manually supply cash with the amount equal to the cash-out amount.

Optionally, before the step of sending the digital currency to a central bank digital currency system, the commercial bank digital currency system further comprises: the commercial bank digital currency system confirms that the digital currency is legal; the commercial bank digital currency system confirming that the digital currency is equivalent to the cash converted amount; the commercial bank digital currency system confirms that the user is a registered user of a commercial bank.

Optionally, before the step of generating a one-time withdrawal code by the central bank digital currency system and then sending the one-time withdrawal code to the user terminal device for presentation to a user, the method further comprises: the central bank digital currency system confirms that the owner of the digital currency is the user.

Optionally, after the step of changing the owner information of the digital currency from the user to the central bank, the central bank digital currency system further includes: the central bank digital currency system records the flow of transactions.

Optionally, the step of the central bank digital currency system generating a one-time withdrawal code and then sending it to the user terminal device for presentation to the user comprises: the central bank digital currency system generating redemption information including a one-time withdrawal code and then sending to the commercial bank digital currency system; the commercial bank digital currency system forwards the redemption information to the user terminal device; and the user terminal equipment extracts the one-time withdrawal code from the cashing information and then presents the one-time withdrawal code to the user.

A second aspect of the present invention provides a system for converting digital currency into physical cash, comprising: user terminal equipment, commercial bank digital currency system and central bank digital currency system, wherein: the user terminal device is configured to: selecting equivalent digital currency in a digital currency wallet according to a cash amount input by external operation; sending the digital currency to the commercial bank digital currency system; the commercial bank digital currency system is to: sending the digital currency to a central bank digital currency system; sending the one-time withdrawal code provided by the user to the central bank digital currency system; sending a money supply instruction after a notice that the one-time withdrawal code is effective is sent, wherein the money supply instruction is used for controlling a machine or prompting a manual cash supply user to manually supply cash with the amount equal to the cash-out amount; the central bank digital currency system is to: generating a one-time withdrawal code and then sending the one-time withdrawal code to the user terminal equipment to be presented to a user, and changing owner information of the digital currency into a central bank by the user; confirming that the one-time withdrawal code is valid, then adding the cash redemption amount to a commercial bank account, and sending a notification to the commercial bank digital currency system that the one-time withdrawal code is valid.

Optionally, the commercial bank digital currency system is further configured to: confirming that the digital currency is legal; confirming that the digital currency is equivalent to the converted cash amount; confirming that the user is a registered user of the commercial bank.

Optionally, the central bank digital currency system is further configured to: confirming that the owner of the digital currency is the user.

Optionally, the central bank digital currency system is further configured to: the transaction flow is recorded.

Optionally, the central bank digital currency system is further configured to generate redemption information including a one-time withdrawal code and then send to the commercial bank digital currency system; the commercial bank digital currency system is further used for forwarding the redemption information to the user terminal device; and the user terminal equipment is also used for extracting a one-time withdrawal code from the cashing information and then presenting the one-time withdrawal code to the user.

In a third aspect, the present invention provides a method for exchanging digital currency into physical cash, including: the user terminal equipment selects equivalent digital currency in the digital currency wallet according to the cash amount input by external operation; the user terminal device sends the digital currency to a commercial bank digital currency system; the commercial bank digital currency system generates a one-time bank withdrawal code and sends the digital currency to a central bank digital currency system; the central bank digital currency system changes owner information of the digital currency into a commercial bank by a user and then sends an owner updating success instruction to the commercial bank digital currency system; the commercial bank digital currency system sends the disposable bank withdrawal code to the user terminal equipment according to the owner updating success instruction so as to present the disposable bank withdrawal code to the user; the commercial bank digital currency system confirms that the one-time-use bank withdrawal code provided by the user is valid, and then issues a supply instruction, wherein the supply instruction is used for controlling a machine or prompting a person to manually pay cash with the amount equal to the cash-out amount.

Optionally, before the step of the commercial bank digital currency system sending the digital currency to a central bank digital currency system, further comprising: the commercial bank digital currency system confirms that the digital currency is legal; the commercial bank digital currency system confirming that the digital currency is equivalent to the cash converted amount; the commercial bank digital currency system confirms that the user is a registered user of a commercial bank.

Optionally, before the step of the central bank digital currency system changing owner information of the digital currency to a commercial bank by a user, further comprising: the central bank digital currency system confirms that the owner of the digital currency is the user.

Optionally, after the step of changing owner information of the digital currency from the user to the commercial bank, the central bank digital currency system further includes: the central bank digital currency system records the flow of transactions.

In a fourth aspect, the present invention provides a system for converting digital currency into physical cash, comprising: user terminal equipment, commercial bank digital currency system and central bank digital currency system, wherein: the user terminal device is configured to: selecting equivalent digital currency in a digital currency wallet according to a cash amount input by external operation; sending the digital currency to a commercial bank digital currency system; the commercial bank digital currency system is to: generating a disposable bank withdrawal code and sending the digital currency to a central bank digital currency system; sending the disposable bank withdrawal code to the user terminal equipment to be presented to a user according to the owner updating success instruction; confirming that the disposable bank withdrawal code provided by the user is valid, and then sending a money supply instruction, wherein the money supply instruction is used for controlling a machine or prompting a user to manually pay cash with the amount equal to the cash-out amount; the central bank digital currency system is to: and changing the owner information of the digital currency into a commercial bank by a user, and then sending an owner updating success instruction to the commercial bank digital currency system.

According to the technical scheme of the invention, the method has the following advantages: (1) due to the adoption of digital currency, the method has the characteristic of paperless property, saves resources and is green and environment-friendly. (2) Because of using digital currency, it can effectively prevent loss, theft, forgery and money laundering. (3) Can counter manual work exchange or self-service machine exchange, it is more convenient. (4) Cash can be redeemed in whole or in part, in batches, with a high degree of freedom and without deadline restrictions.

Drawings

The drawings are included to provide a better understanding of the invention and are not to be construed as unduly limiting the invention. Wherein:

FIG. 1 is a schematic diagram of the main flow of the operation of a prefabricated card in connection with an embodiment of the present invention;

FIG. 2 is a schematic diagram of a process for a user to register a D-RMB account in connection with an embodiment of the invention;

FIG. 3 is a schematic diagram of a D-RMB transaction process relating to an embodiment of the present invention;

FIG. 4 is a diagram illustrating one configuration of an overall framework when the D-RMB digital money system provides online services according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a computer system included in a commercial bank digital currency system according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an architecture for interconnecting a commercial bank digital currency system with external systems, in accordance with an embodiment of the present invention;

FIG. 7 is a schematic diagram of the main steps of a method of converting digital currency into physical cash according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of the major modules of a system for converting digital currency to physical cash, according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of the main steps of another method of converting digital currency into physical cash according to an embodiment of the present invention;

fig. 10 is a schematic diagram of the main modules of another system for converting digital currency into physical cash according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention are described below with reference to the accompanying drawings, in which various details of embodiments of the invention are included to assist understanding, and which are to be considered exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness.

In the embodiment of the invention, a digital currency (hereinafter referred to as D-RMB) design scheme based on crypto-mathematics is described, and the main operation mode is that a central bank and each commercial bank together build a D-RMB system in a grading way. The central bank here is a currency issuing organization, such as the chinese people's bank. In the following description, a central bank is sometimes simply referred to as a "central bank", and similarly, a commercial bank is sometimes simply referred to as a "business bank". Further, the digital money is denoted by "D_{Coin (coin)}”。

The D-RMB system is based on D_{Coin (coin)}A funds transfer system for transactions operated jointly by a central bank with commercial banks. The D-RMB system includes a core service operating in a particular digital centerOn the device D_{Coin (coin)}The system comprises an issuing module, a client login module, a client account management module, a transaction management module, a fraud detection module and a core service module, and also comprises terminal client programs needing to interact with a core server, such as a mobile phone and a notebook computer of a user end, and also comprises a server D_{Coin (coin)}The funds-transfer system operates over an open form of electronic communications network, including the internet, mobile communications networks, and so on, nationwide. Before discussing the D-RMB system, it is clear that:

1. and the method is compatible with the current physical currency circulation. The digital currency in the D-RMB system is stored through three links, namely a digital currency issuing bank at the central bank (namely digital currency fund); the bank of the commercial bank, namely the stock digital cash of the commercial bank; and thirdly, a client application program at the user end, namely the electronic wallet. During this different process, the D-RMB registration center will complete the relevant registration operation.

D-RMB digital currency does not use blind signatures. Limited anonymous protection during use.

The 3.D-RMB digital currency can be circulated by different networks, and can be stored in various electronic equipment terminals such as mobile phones, IC card chips, notebook computers and the like in an electronic digital form, and the discussion is mainly carried out by taking the mobile phones and the IC cards as carriers to store the D-RMB digital currency, but the D-RMB digital currency is not limited to only taking the mobile phones and the IC cards as the carriers.

The payment mode for the D-RMB system design relies on the transfer of D-RMB digital currency (i.e., D: D)_{Coin (coin)}Transaction).

5, the D-RMB system is subject to the relevant system requirements of cash management in China. The specific requirements are determined by the requirements of the business department.

6. To avoid a homogeneous competition with existing billing payment systems, the D-RMB system may be designed for limited-line payments.

To facilitate the subsequent description, the following notation is given:

enc: and encrypting, namely after downloading a private key from the IBC center, a user signs the sent information with the private key of the user and encrypts the information with the public key of the other party.

And Dec: and decrypting, specifically, the user decrypts the incoming text by using the own private key, and signs and confirms the information sent by the user by using the mobile phone number of the opposite party as a corresponding public key (or a direct public key).

D_Bank: the bank is a deposit account opened in the central system of the central bank for accounting.

D_{Coin (coin)}: the D-RMB digital currency generated by the finger row according to the own encryption mechanism is a string of characters and represents a certain amount of RMB.

D_{Coin 100}: D-RMB digital currency generated by the instruction row according to an own encryption mechanism is a string of numbers and represents 100 yuan RMB, and the like, and subscript numbers represent the actual RMB amount.

B_{Account number}: the bank account number of the bank where the user is located.

H (M): the hash operation is performed on M to obtain a value, where M may be a mobile phone number, an organization code, or a string of characters and numbers.

The D-RMB is used as digital currency, established by China's bank as legal currency, issued into circulation, and used as final credit to provide guarantee to participate in exchange, remittance and consumption in national standard architecture. It is a string of codes with the same monetary meaning as the "face value" in actual circulation. D-RMB digital currency simulates the issuing and managing process of paper currency in the central row, and digital currency is generated at one time according to the issuing amount of the current digital currency in the central row in a D-RMB issuing bank.

In the design of D-RMB system, D_{Coin (coin)}The system can be generated according to the minimum unit denomination, the specific withdrawal amount of a user, the real-object currency denomination in circulation, and the specific mode which can be set in the initial process through system parameters. For the sake of closeness, the fixed denomination in circulation is taken as an example for the following explanation.

The D-RMB in the distribution library completely simulates the face value in circulation, the printing generates digital representation of 'one circle, five circle, puzzling circle, two puzzling circle, five puzzling circle, one herborist circle' and the like, and the encrypted text represents the D-RMB digital currency of the face value.

Producing D-RMB at a fixed denomination, e.g., producing a representative D-RMB according to the fifth set (production required: D)_{Coin 1}、D_{Coin 5}、D_{Coin 10}、D_{Coin 20}、D_{Coin 50}、D_{Coin 100}) Then:

step 1: six basic encryption ciphers are generated from the master cipher and the numbers 1, 5, 10, 20, 50 and 100, respectively.

Step 2: the system random number is generated by a hash algorithm. The random number may be understood as a crown number.

And step 3: the encryption password is generated by encrypting a basic encryption password representing different currency values and a random number.

And 4, step 4: the secret password is signed by the private key of the central row, and represents the generation of a new coin. If the payee wants to provide D representing 100 Yuan RMB_{Coin 100}Then, in the actual withdrawal process, the unique random number representing 100 yuan and the corresponding basic encryption password can be encrypted to generate an encryption ciphertext m, and then the secret key at the central row signs the m.

In the D-RMB system, there are a digital money issuing bank at the central bank, a digital money bank at a commercial bank, and an electronic wallet at a user side (e.g., a mobile phone). The basic content of digital money transfers includes:

(1) according to the total amount of issued digital money, digital money (i.e., the fund for digital money) is generated at the central bank and stored in the central bank.

(2) According to the demand application of the digital currency of the commercial bank, the digital currency is sent to a database of the corresponding commercial bank for storing the digital currency, namely the digital currency is sent from an issuing bank to a bank.

For example, 10 hundred million D-RMB are issued by the central row at a certain time according to the total amount of money issued, and these D-RMB are released in the issuing bank of the central row after being issued. Later, 2 billion of the 10 billion D-RMBs are extracted from the 10 billion D-RMBs according to the application of a certain bank, the extracted 2 billion D-RMBs are stored in the bank of the bank (the bank accounts for the deposit preparation money at the central bank are reduced by 2 billion, meanwhile, 2 billion D-RMBs are stored in the bank of the commercial bank, the operation of the bank accounts is equal to the payment of the current real money), and at the registration center, the owner corresponding to the digital money is changed from the central bank to the commercial bank, and the information of the corresponding operation flow and the like is recorded.

(3) When a user applies for extracting digital money, the digital money enters a storage medium (such as a mobile phone) of a user client from a bank to a circulation link, namely from the bank to an electronic wallet of the user. In the registration center, the owner corresponding to the digital currency is changed into the user by the commercial bank, and the information such as the corresponding operation flow is recorded.

(4) In the circulation link, the essence of the digital money is to transfer between the electronic purses of two users to complete payment, and the payment is divided into online transaction and offline transaction, and the detailed business process is analyzed in detail later. In the registration center, the owner corresponding to the digital currency is changed from the user 1 to the user 2, and information such as corresponding operation flow is recorded.

In the above digital money transfer process, the registration center of the D-RMB system needs to verify the validity of the transaction digital money, record the transaction flow and correct the new owner of the corresponding digital money, and register other required information (specifically determined by the business requirements).

If the IC card is used as a carrier, the work of preparing the card exists, and in the work of preparing the card, a central bank digital currency system and a commercial bank digital currency system carry out a series of operations on a D-RMB chip card containing a storage medium, and the operations mainly comprise: the central bank digital currency system generates personalized data of the D-RMB chip card according to the pre-designated content; the commercial bank digital currency system writes personal information of a user applying for the D-RMB chip card into the D-RMB chip card; the commercial bank digital currency system applies an IBC private key to the authentication system by using a user IBC public key, wherein the user IBC public key is the identification of the D-RMB chip card or the identification of the user. The main flow involved in the above operations is shown in fig. 1, and fig. 1 is a schematic view of the main flow of the operation of the prefabricated card relating to the embodiment of the present invention.

As a card base D_{Coin (coin)}The safety vector of (2), in D_{Coin (coin)}Each link of circulation is to guarantee D_{Coin (coin)}The security of (A) has a certain reinforcing effect (an independent physical carrier IC card is also called as 'D-RMB chip card' for short) ")。

(1) Production of D-RMB chip cards

The production of D-RMB chip cards must be produced by a company certified by a central bank with production qualifications for which the quantity and quality of the production manufacture is strictly controlled by the central bank (or other departments authorized by the central bank). The enterprise qualification authentication process comprises the following steps: submitting an application, examining and verifying materials, detecting a sample card, evaluating on site, authorizing qualification and the like.

(2) Personalization of D-RMB chip cards

The personalized data in the D-RMB chip card is generated by a central bank, and related departments are authorized to establish a personalized center to perform personalized operation on the newly produced D-RMB chip card.

(3) Issuing of D-RMB chip cards

The system can support real-name card issuing and anonymous card issuing.

Card issuing in a real name system: the D-RMB chip card is applied by the user, the card is issued in real name, the central bank authorizes the commercial bank to issue the card, the commercial bank checks the real name of the user and registers the related data, after the check is passed, the secondary card issuing is carried out on the D-RMB chip card of the central bank, and the personal information of the user is written into the D-RMB chip card.

Anonymous card issuing: the user directly applies the D-RMB chip card to the commercial bank, and the commercial bank can select whether to verify the identity information of the applicant according to the actual situation.

And the commercial bank selects the unique identification number of the D-RMB chip card or the mobile phone number of the user as the public key of the IBC of the user according to the actual situation, and further applies for the private key from the IBC authentication center.

The D-RMB system supports the selection of online or offline transactions using computer devices, mobile phones, POS, ATM, and Web as carriers, and the examples herein will be mainly described using mobile phones as carriers.

With regard to the mobile phone terminal, various unlocking settings such as digital passwords, graphic passwords and the like and power-on passwords can effectively protect the security of personal information on the mobile phone. With the coming of the smart phone era, various fingerprint mobile phones based on biological characteristics enter common consumer groups, different fingerprint encryption can be adopted according to different applications and different specific information, and the application of the new technologies can effectively ensure the storage safety of digital currency and related transaction information on the mobile phones.

In order to ensure the safety of the transfer of the digital currency between the mobile phones, a safety certification system needs to be introduced into the D-RMB system. The existing CA authentication center is utilized between the central bank and the financial institution, and social users (including individuals and enterprises) can utilize an IBC (Identity-Based cryptography) authentication center to perform Identity authentication.

For private keys and public keys in a central row generated in IBC and PKI, Secure Element (SE) is required to be stored in a Secure exclusive area of a mobile phone, and the SE area may be implemented by hardware (mobile phone Card change) or host Card emulation (hce). If the user adopts the card change to protect the secret key, the secret key is downloaded to the SE area of the mobile phone in the card change application process.

In the construction process of the authentication system, the PKI system can be designed according to the traditional PKI authentication system, the PKI system is uniformly established, a CA (certificate authority) provides a strong digital signature, the PKI system can also be designed according to an IBC (identity based certificate), and a user mobile phone number is taken as a public key to manage, so that the PKI system seems to be more convenient and fast especially for off-line payment of a tiny amount. All business introductions below will be explained in terms of IBC authentication. Fig. 2 is a schematic diagram of a process of registering a D-RMB account by a user in connection with an embodiment of the present invention, and fig. 3 is a schematic diagram of a D-RMB transaction process in connection with an embodiment of the present invention.

When registering a user, the following procedures are mainly performed: after receiving the identification information sent by the terminal equipment used by the user, the central bank digital currency system sends application software suitable for the terminal equipment to the terminal equipment; the central bank digital currency system sends an IBC public key and an IBC private key to the terminal equipment running the application software, and then performs identity authentication session and session key negotiation with the terminal equipment; and the central bank digital currency system receives the user account sent by the terminal equipment running the application software and then sends a user password to the terminal equipment.

50-dollar digital currency D for online payment of user 1 to user 2_{Coin 50}For example, the transaction is describedIn the equation relating to D_{Coin 50}Security protocol at transfer time. The user 1 logs in the APP of the mobile phone of the user to complete the identity authentication of the two parties with the D-RMB system, and executes a transaction protocol after a session key is negotiated in an SSL mode. Taking a mobile phone number as an IBC public key as an example, at a mobile phone client of the user 1: mobile phone client automatically selects 50-yuan digital currency D_{Coin 50}The related information M | M is organized according to transaction rules, where M may be designed to: m | mobile phone number 1 | D |, transaction code |_{Coin 50}The payment amount | mobile phone number 2, the information segment is subjected to hash operation to obtain a message H (M), a private key pair H (M) corresponding to the mobile phone number 1 is used for signing to obtain M, and the M | M is sent to the D-RMB system in an encryption mode.

D-RMB system end: decrypting the message according to a protocol to obtain M | M, and verifying the validity of the message, namely verifying M and H (M) by using a public key, namely a mobile phone number 1, so as to prevent the message from being tampered in the transmission process; verification D_{Coin 50}If it is legal, the transaction rule and related information are read and the corresponding operation is executed, which mainly includes the change of registration center after service verification_{Coin 50}And the owner changes the bound mobile phone number 1 into a mobile phone number 2 and records the corresponding running water. Sending D_{Coin 50}And the mobile phone 2 is given, and the successful transaction is prompted to the two parties.

In order to further enhance anonymity, the mobile phone number corresponding to the right of the registration center can be changed into the hash of the mobile phone number (i.e. borrowing the address of the bitcoin wallet, which consists of public key hash), which is specifically described as follows:

the client side organizes the message unchanged, and at the mobile phone client side of the user 1: automatic selection of 50-dollar digital currency D_{Coin 50}The related information M | M is organized according to the transaction rule, wherein M may be designed as a transaction code | mobile phone number 1 | D_{Coin 50}The payment amount | mobile phone number 2, the information segment is subjected to hash operation to obtain a message H (M), a private key pair H (M) corresponding to the mobile phone number 1 is used for signing to obtain M, and the M | M is sent to the D-RMB system in an encryption mode.

D-RMB system end: decrypting the message according to a protocol to obtain M | M, and verifying the validity of the message, namely verifying M and H (M) by using a public key, namely a mobile phone number 1, so as to prevent the message from being tampered in the transmission process; verification D_{Coin 50}Whether it is legal, interpreting transaction rules and related information, performing corresponding operations, main packageIncluding post-service validation registry changes D_{Coin 50}And the owner changes the bound H (mobile phone number 1) into H (mobile phone number 2), and records the corresponding running water. Sending D_{Coin 50}And the mobile phone 2 is given, and the successful transaction is prompted to the two parties.

With respect to system convenience design, in embodiments of the present invention, there are a variety of interfaces and portals for transactions. In the scene example process, only one entrance is used for example, if a registered user transacts business in a commercial bank, the user can directly log in the D-RMB system by taking a mobile phone, and the commercial bank can log in the D-RMB system.

Regarding the problem of the account password, whether the user needs to input the account password can be flexibly designed according to the business needs. Based on the D-RMB system being a micropayment system, the proposal may consider whether to set a password freely selected by the user. In the description of the embodiments of the present invention, the description is made without leaving a password, but in the implementation, the description may be made according to the actual situation.

Regarding the problem of the client application program, the user can download the corresponding client application program on the corresponding terminal (such terminal software is equivalent to a "wallet" tool), for example, the mobile phone user can download the D-RMB mobile phone terminal program (also called as mobile phone APP). The terminal program may be designed to include the following functions: one is D_{Coin (coin)}And (5) management functions. (1) The terminal program can automatically count all D_{Coin (coin)}An amount; (2) can automatically find D in the wallet according to the amount of money input by the user_{Coin (coin)}Combining and automatically selecting matched D in the payment process_{Coin (coin)}Performing a transaction; (3) after the transaction is completed, D for participating in expenditure is automatically selected_{Coin (coin)}Deleting; (4) the digital currency which is not checked in the center row in the wallet can be automatically distinguished from the checked and registered digital currency. And secondly, completing the functions required by the business, such as business functions of online registration application, extraction, payment, cashing, offline payment request and the like, and automatically completing operations of public key encryption, private key signature and the like in the transaction process.

In general, the core elements of the D-RMB system are a currency, two types of libraries and three centers:

a coin, namely D-RMB ", also known as D_{Coin (coin)}In particular to a series of encrypted digital strings representing a specific amount signed by a central line.

Two types of libraries: respectively an issuing bank and a banking bank of the D-RMB. The digital currency is expressed as digital currency fund at the central row in the issuing bank; the digital currency is presented in the bank vault as digital cash in stock by the commercial bank.

Three centers: the first is a registration center (including currency generation, circulation, counting, check and death whole process record); the other two are the certification centers, namely the CA certification center (Based on the PKI system, centralized management of the certificates of organizations and users, such as CFCA) and the IBC certification center, namely the certification center established Based on the cryptographic technology of identification (Identity-Based cryptography). Two tables can be designed in the registration center, one is a digital currency ownership registration table for recording the attribution of digital currency, and the other is a transaction flow meter.

The identity-based cryptosystem IBC in the embodiment of the invention can directly use the identity of the user as a public key, the authentication of the public key is not dependent on a certificate any more, the use and management of the secret key are simplified, and the identity-based cryptosystem IBC has the advantages of no catalogue, convenience in use, easiness in maintenance and the like.

For the identity identification, the individual user can adopt a mobile phone number, and also can adopt an E-mail address matched with the mobile phone or other converted character strings, so that the individual user can conveniently memorize the identity identification, and other people can not know the identity identification), and the purpose of controllable anonymity can be achieved. Enterprise users may use an organization code or a custom code as an identity of the IBC center, and the identity is used as a public key, which is described in the following example only by using a mobile phone number as an example.

The D-RMB system is a hierarchical system, namely, a central bank and each commercial bank are built together, the central bank digital currency system is a computer system which is operated and maintained by the central bank or a designated organization of the central bank and is used for processing information about digital currency, the main functions of the central bank digital currency system comprise the responsibility for issuing and verifying and monitoring the digital currency, the commercial bank is a computer system which is operated and maintained by the commercial bank or the designated organization of the commercial bank and is used for processing the information about the digital currency, the commercial bank performs various functions about the currency of the existing bank, namely bank functions, and the D-RMB system mainly comprises the responsibility for directly facing the society after applying for the digital currency from the central bank, and meets various requirements for providing digital currency circulation services.

In the basic structure of the digital money system according to the embodiment of the present invention, the digital money system mainly includes a central bank digital money system, a commercial bank digital money system (which may be a plurality of commercial bank digital money systems in practice), and an authentication system. The central bank digital currency system is used for generating and issuing digital currency and performing ownership registration on the digital currency; a commercial bank digital currency system for performing banking functions on digital currency; the authentication system is used for providing authentication for interaction between the central bank digital currency system and a terminal device used by a user of digital currency, and for providing authentication for interaction between the central bank digital currency system and the commercial bank digital currency system.

Fig. 4 is a schematic diagram of one structure of an overall framework when the D-RMB digital money system provides an online service according to an embodiment of the present invention.

In the overall framework shown in fig. 4, the core of the D-RMB digital currency operation is the commercial bank digital currency system, and the central bank D-RMB system is connected to the merchant bank D-RMB system and is responsible for transaction confirmation. The commercial D-RMB system and the central D-RMB system can fully utilize advanced cloud technology to carry out decentralized deployment, and meanwhile, the commercial D-RMB system is interconnected and communicated with internal systems thereof.

As can be seen from the figure, the commercial bank digital currency system is connected with other networks or systems at a core position, and can be constructed by applying the technology of 'cloud computing'. The D-RMB digital currency system supports network data of various protocols, such as Virtual Private Networks (VPNs), private lines, satellite networks, Public Switched Telephone Networks (PSTN), global system for mobile communications (GSM), Public Land Mobile Networks (PLMNs), and different networks can be directly or indirectly connected with the central server.

The business digital currency system is connected with a central bank registration center and also comprises four basic functional modules: the system comprises an electronic wallet function module for automatically tracking the amount of D-RMB digital money owned by an account, a supervision function module for automatically tracking the transfer of the D-RMB digital money among all parties and identifying suspicious transactions, an electronic banking function and a Customer Relationship Management (CRM) function module.

The logical layout of the server in the commercial bank digital currency system adopts a three-layer architecture mode: namely, the presentation layer, namely, the front-end application system 200; a back-end application system 202, also called a session layer, an application layer, or a transaction logic layer; the background database 204 is a data layer. A corresponding physical machine deployment block diagram is shown in fig. 5, and fig. 5 is a schematic diagram of a computer system included in a commercial bank digital currency system according to an embodiment of the present invention.

The front-end application 200 is an application, such as a Web application, deployed here as a Web server cluster, for running users that interact directly with money transfer service operators. The user and money transfer service operator interact with these applications through a user interface, such as a personal computing device 114 and a mobile device. The user can access the functions of the electronic wallet, the supervision function, the virtual bank function and the CRM function through the entrance. Open source software such as apache can be adopted on the Web server.

The back-end application system 202 is mainly used to support the back-end functions of the front-end application system 200, such as data access, business logic processing, and the like. This area deploys the application servers. D-RMB digital currency can use JBOSS tool under Red Hat open source system to develop applications.

The back-office database 204 is essentially a database management system DBMS that includes a data repository that stores sales transactions for transferring money, customer profiles, and other data needed to track and regulate the central bank digital money system for D-RMB digital money transfers. The D-RMB digital currency system can be designed using Oracle's DBMS as a database system.

The digital currency system of the business department can be interconnected with an external system, and an alternative architecture is shown in fig. 6, and fig. 6 is a schematic diagram of an architecture for interconnecting the digital currency system of the commercial bank with the external system according to the embodiment of the invention.

The above figure illustrates the physical and logical layout of a commercial bank digital currency system with various external system adapters including central bank servers, other commercial bank systems. There are monetary transaction data adapters, cell phone service provider SMS gateway adapters, retailer system adapters, ATM data supply system adapters, etc. by means of this interconnection the central server can accept digital monetary transfer requests and responses from each type of entity. Fig. 6 illustrates well the support of the D-RMB digital currency system to various channels, different protocol networks, which is also a manifestation of its open nature.

The following describes various business processes of operating the D-RMB by taking a user mobile phone as a terminal mode and a mobile phone number as an identity, and mainly describes the processes of downloading and logging, extracting, paying, depositing, cashing and the like by a client side and a face-to-face transaction mode. The client login, extraction and cashing processes of the user require that the user needs to complete in an online state, the payment process can be divided into online payment and offline payment, so a plurality of scene states and corresponding processes are formed, and the aim of each process is achieved by a series of operation steps. In addition to the mobile phone, other intelligent terminals which may appear at present and in the future can be used as carriers of the D-RMB and perform various service processes.

The outline of the flow (hereinafter, "flow explanation") and the scene state (hereinafter, "scene explanation") and the steps of realizing the flow in the scene (hereinafter, "step explanation") are described below one by one, respectively.

The downloading and logging of the user client side are executed according to the following procedures:

description of the flow: the user downloads an APP installation program provided by a commercial bank through a mobile phone to log in the D-RMB system process.

Scene description: and a qualified commercial bank (such as an industrial and commercial bank) is connected with the CA authentication center, the IBC authentication center and the registration center to provide digital currency services for the user. The user downloads an APP installation program provided by the commercial bank through the mobile phone to log in the commercial bank D-RMB system.

Description of the steps:

step 1, a user logs in a D-RMB system page of a business (such as a Chinese industrial and commercial bank) by a mobile phone, downloads a mobile phone APP installation program provided by the commercial bank, and can directly log in a user with an existing account number (IBC authentication center); for a new user, account initialization operations need to be performed first.

Step 2, initialization: inputting related information (such as name, address, e-mail address, mobile phone number, identity card number, registered account number, namely mobile phone number) on the page, and clicking to send.

Step 3, commercial bank: connecting with an IBC authentication center, creating a unique account number of the D-RMB digital currency system for the user, and verifying the uniqueness of the account number at the IBC authentication center. An individual user can adopt a mobile phone number to generate a user initial login password and send the user initial login password to a user mobile phone; the IBC center generates a private key of the user according to the mobile phone number, the public key is the mobile phone number of the user, and the public key is used as an account number for transaction circulation.

Step 4, the user mobile phone end: and activating an account after receiving the initial login password, downloading a user private key and a public key of a central bank to a mobile phone security protection area, and modifying the login password by logging in the mobile phone APP again to complete initialization.

If the user applies for changing the mobile phone card, the key can be pre-planted in the SE area of the card in advance.

The method and system for converting digital currency into physical cash in the embodiments of the present invention will be described in further detail below.

Fig. 7 is a schematic diagram of the main steps of a method of converting digital currency into physical cash according to an embodiment of the present invention. As shown in fig. 7, the method of converting digital currency into physical cash of this embodiment may include steps a1 through a7 as follows. The method is applicable to the system B for converting digital currency into physical cash of the embodiment of the present invention described later.

Step A1: the user terminal device selects digital money of the same value in the digital money wallet according to the amount of cash exchanged inputted by an external operation.

For example, the user is a registered user of a commercial bank, and the user terminal equipment is a mobile phone client developed by the commercial bank. After a user inputs a user name and a password to log in a mobile phone client, clicking and selecting a cashing function, and then inputting a cashing amount of 100 yuan to user terminal equipment. This means that the user terminal device receives a redemption instruction including a redemption amount inputted by an external operation. Thus, the total amount of the user terminal device in the digital money wallet is equal to the amount of the digital money to be redeemed. Suppose that a digital currency D with an amount of 100 dollars is selected at this time_{Coin 100}。

It should be noted that the user may be a registered user of the commercial bank or an unregistered user of the commercial bank. When the user is a registered user of the commercial bank, the withdrawal password is required to be input.

Step A2: the user terminal device sends the digital money to the commercial bank digital money system.

Specifically, the method comprises the following steps: the mobile phone client can organize related information according to preset transaction specifications to generate digital currency D_{Coin 100}Then sent to the commercial bank digital currency system.

Optionally, prior to performing step a3, the commercial bank digital currency system may perform a first validation according to the first message as follows: the commercial bank digital currency system verifies the validity of the digital currency according to the first message; the commercial bank digital currency system verifies whether the digital currency is equivalent to the cash amount according to the first message; and the commercial bank digital currency system verifies whether the user is a registered user of the commercial bank according to the first message. It should be noted that the specific content of the first message and the first verification may be flexibly set according to the transaction rule, and this is only an example and is not a limitation of the present invention. If the first verification passes, step A3 is performed. If the first authentication fails, the flow ends.

Step A3: the commercial bank digital currency system sends digital currency to a central bank digital currency system.

Specifically, the commercial bank digital currency system can organize related information according to preset transaction specifications to generate the digital currency D_{Coin 100}Then sends the second message to the central bank digital goodsCoin system.

Optionally, before performing step a4, the central bank digital currency system may perform a second verification according to the second message as follows: and the central bank digital currency system verifies whether the owner of the digital currency is the user according to the second message. It should be noted that the specific contents of the second message and the second verification may be flexibly set according to the transaction rule, and this is only an example and is not a limitation of the present invention. If the second verification passes, step A4 is performed. If the second authentication fails, the flow ends.

Step A4: the central bank digital currency system generates a one-time withdrawal code and then sends it to the user terminal device for presentation to the user, and changes owner information of the digital currency from the user to the central bank.

Specifically, the central bank digital currency system may organize the relevant information according to preset transaction specifications to generate a one-time valid one-time withdrawal code for the user to withdraw money. The generation of the withdrawal code may be followed by a direct or indirect transmission to the user terminal device for presentation to the user. After the user terminal device presents the one-time withdrawal code, the user can withdraw money by self from an automatic withdrawal machine of the commercial bank or withdraw money by manpower from an artificial counter of the commercial bank by the aid of the one-time withdrawal code.

Alternatively, in the scheme of the above-mentioned "central bank digital currency system generates a one-time withdrawal code and then indirectly sends it to the user terminal device for presentation to the user", the specific steps may include: the central bank digital currency system generates cashing information comprising the one-time withdrawal code and then sends the cashing information to the commercial bank digital currency system; the commercial bank digital currency system forwards the cashing information to the user terminal equipment; the user terminal device extracts the one-time withdrawal code from the redemption information and then presents the one-time withdrawal code to the user. In the scheme, the commercial bank digital currency system cannot directly acquire the one-time withdrawal code from the cashing information so as to prevent the commercial bank from stealing the funds of the user.

Central bank digital currency system outside of "generate and send one-time withdrawal code" operationAlso, the digital currency D is changed in a registry within the central bank digital currency system_{Coin 100}Is the code of the central bank changed from the digital money wallet. This means that the issuing bank of the central bank has collected the digital money D_{Coin 100}. Optionally, the central bank digital currency system also records the corresponding transaction flow after the digital currency owner information is changed.

Step A5: the commercial bank digital currency system transmits the one-time withdrawal code provided by the user to the central bank digital currency system.

Specifically, taking the example of a user getting a cash to a commercial bank counter, the commercial bank counter staff enters a one-time withdrawal code provided by the user (and also correspondingly enters an operation code of the bank) on a teller machine (which can be regarded as an interface of the commercial bank digital currency system for receiving external information). The merchant bank digital currency system then sends the transaction information including the one-time withdrawal code to the central bank digital currency system.

Step A6: the central bank digital currency system confirms that the one-time withdrawal code is valid, then increments the commercial bank account by the cash redemption amount, and sends a notification to the commercial bank digital currency system that the one-time withdrawal code is valid.

Specifically, the central bank digital currency system makes a conditional judgment on the one-time withdrawal code to verify whether it is valid. If the verification passes, the bank account D is checked_BankAdding 100-element accounting and feeding back the relevant results to the commercial bank. If the verification fails (e.g., the one-time withdrawal code has been redeemed and is thus invalid), the process ends.

Step A7: and the commercial bank digital currency system sends a money supply instruction after receiving the notification, wherein the money supply instruction is used for controlling the machine or prompting a person to pay cash with the amount equal to the cash amount of the cash redemption amount.

Fig. 8 is a schematic diagram of the main modules of a system for converting digital currency into physical cash according to an embodiment of the present invention. As shown in fig. 8, the system B for converting digital money into physical cash of this embodiment may include: user terminal device B1, commercial bank digital currency system B2 and central bank digital currency system B3.

The user terminal device B1 is configured to: selecting equivalent digital currency in a digital currency wallet according to a cash amount input by external operation; the digital currency is sent to the commercial bank digital currency system B2.

Commercial bank digital currency system B2 is used to: sending the digital currency to a central bank digital currency system B3; sending the user-supplied one-time withdrawal code to the central bank digital currency system B3; and sending a money supply instruction after the notification that the one-time withdrawal code is effective is sent, wherein the money supply instruction is used for controlling the machine or prompting a user to manually pay cash with the amount equal to the cash-out amount.

The central bank digital currency system B3 is used to: generates a one-time withdrawal code and then transmits it to the user terminal device B1 to be presented to the user, and changes the owner information of the digital money from the user to the central bank; confirm that the one-time withdrawal code is valid, then increment the commercial bank account by the cash redemption amount, and send a notification to the commercial bank digital currency system B2 that the one-time withdrawal code is valid.

Optionally, the commercial bank digital currency system B2 is further operable to: confirming that the digital currency is legal; confirming the equivalence of the digital currency and the cash amount; confirming that the user is a registered user of the commercial bank.

Optionally, the central bank digital currency system B3 is further configured to: confirming that the owner of the digital currency is the user.

Optionally, the central bank digital currency system B3 is further configured to: the transaction flow is recorded.

Optionally, the central bank digital currency system B3 is also operative to generate redemption information including the one-time withdrawal code and then send to the commercial bank digital currency system B2; the commercial bank digital currency system B2 is also used to forward redemption information to the user terminal device B1; and the user terminal device B1 is also used to extract the one-time withdrawal code from the redemption information and then present the one-time withdrawal code to the user.

Fig. 9 is a schematic diagram of main steps of another method for converting digital money into physical cash according to an embodiment of the present invention. As shown in fig. 9, the method of converting digital money into physical cash of this embodiment may include steps C1 to C6 as follows. The method is applicable to the system D for converting digital currency into physical cash of the embodiment of the present invention described later.

Step C1: the user terminal device selects digital money of the same value in the digital money wallet according to the amount of cash exchanged inputted by an external operation.

Step C2: the user terminal device sends the digital money to the commercial bank digital money system.

Optionally, before performing step C3, the following steps may be further included: the commercial bank digital currency system verifies the validity of the digital currency; the commercial bank digital currency system verifies whether the digital currency is equivalent to the cash amount; the commercial bank digital currency system verifies whether the user is a registered user of the commercial bank. If the verification passes, step C3 is performed. If the verification fails, the flow ends.

Step C3: the commercial bank digital currency system generates a one-time-use home bank withdrawal code and sends the digital currency to the central bank digital currency system.

Optionally, before step C4, the method may further include: the central bank digital currency system verifies whether the owner of the digital currency is the user. If the verification passes, step C4 is performed. If the verification fails, the flow ends.

Step C4: the central bank digital currency system changes owner information of the digital currency from the user to the commercial bank and then sends an owner update success instruction to the commercial bank digital currency system.

Optionally, after the step of the central bank digital currency system changing owner information of the digital currency from the user to the commercial bank, the method may further include: the central bank digital currency system records the flow of transactions.

Step C5: and the commercial bank digital currency system sends the disposable bank withdrawal code to the user terminal equipment according to the owner updating success instruction so as to present the disposable bank withdrawal code to the user.

So far, after seeing the one-time withdrawal code presented by the user terminal device, the user can use the one-time withdrawal code to self-service withdraw money from an automatic withdrawal machine of the commercial bank or manually withdraw money from an artificial counter of the commercial bank. It should be noted that the user may not go to other commercial banks or a central bank to withdraw money.

Step C6: the commercial bank digital currency system validates the one-time bank withdrawal code provided by the user and then issues a supply instruction for controlling the machine or prompting the user to manually dispense cash in an amount equal to the cash-out amount.

Specifically, the commercial bank digital currency system verifies that the user-supplied one-time-use-bank withdrawal code is valid. If the disposable bank withdrawal code is valid, a money supply instruction is sent. If the one-time-use bank withdrawal code (e.g., the one-time-use bank withdrawal code was redeemed and is invalid), the process ends.

Fig. 10 is a schematic diagram of the main modules of another system for converting digital currency into physical cash according to an embodiment of the present invention. As shown in fig. 10, the system D for converting digital money into physical cash of this embodiment may include: a user terminal device D1, a commercial bank digital money system D2, and a central bank digital money system D3.

The user terminal device D1 is configured to: selecting equivalent digital currency in a digital currency wallet according to a cash amount input by external operation; the digital currency is sent to the commercial bank digital currency system D2.

The commercial bank digital currency system D2 is used to: generating a one-time bank withdrawal code and sending the digital currency to the central bank digital currency system D3; according to the owner updating success instruction, sending the disposable bank withdrawal code to the user terminal device D1 to be presented to the user; confirming that the one-time bank withdrawal code provided by the user is valid, and then sending a supply instruction, wherein the supply instruction is used for controlling a machine or prompting a person to manually pay cash with the amount equal to the cash-out amount.

The central bank digital currency system D3 is used to: the owner information of the digital money is changed to the commercial bank by the user, and then an owner update success instruction is sent to the commercial bank digital money system D2.

Optionally, the commercial bank digital currency system D2 is further configured to: confirming that the digital currency is legal; confirming the equivalence of the digital currency and the cash amount; confirming that the user is a registered user of the commercial bank.

Optionally, the central bank digital currency system D3 is further configured to: confirming that the owner of the digital currency is the user.

Optionally, the central bank digital currency system D3 is further configured to: the transaction flow is recorded.

From the above, the method and system for converting digital currency into physical cash of the embodiments of the present invention have at least the following advantages: (1) due to the adoption of digital currency, the method has the characteristic of paperless property, saves resources and is green and environment-friendly. (2) Because of using digital currency, it can effectively prevent loss, theft, forgery and money laundering. (3) Can counter manual work exchange or self-service machine exchange, it is more convenient. (4) Cash can be redeemed in whole or in part, in batches, with a high degree of freedom and without deadline restrictions.

Repetitive transaction detection is described below. In the case of online transactions, the D-RMB system passes through D_{Coin (coin)}And the user account is bound to prevent repeated transactions. The registration center in the D-RMB system has a rights registration form, and the record form pattern can be designed as shown in Table 1:

TABLE 1

Digital currency name	Owner of an animal	Remarks for note
			Pbc100adfkl09987766670	138xxxxx 001	D_{Coin 100}
……	……	……
			Pbc50cadfkl09987766670	137xxxxx 002	D_{Coin 50}

User 1 (cell phone number 138xxxxx001) is paying D to user 2 (cell phone number 138xxxxx002)_{Coin 100}In the process, the D-RMB system registers a central ownership registration form: modification of D_{Coin 100}Corresponding to the owner, the wallet address of the original mobile phone number 138xxxxx001 in the owner field is changed into the wallet address of the mobile phone number 138xxxxx002, if the user 1 also wants to use D_{Coin 100}The payment to other users, whose owner is not the user 1, can not be completed, thereby preventing the repeated payment.

If the registry authority ownership registry represents the owner with a public key hash in the D-RMB system, the registry authority ownership registry can be designed as table 2:

TABLE 2

Assuming that H (138xxxxx001) has a value of 1Xadcfdgdadg and H (138xxxxx002) has a value of 2xcfdald3xgdf, user 1 (mobile phone number 138xxxxx001) pays for D to user 2 (mobile phone number 138xxxxx002)_{Coin 100}In the process, the D-RMB system registers a central ownership registration form: modification of D_{Coin 100}Corresponding to the owner, 1Xadcfdg in the owner fielddadg is changed to 2xcfdald3xgdf if user 1 also wants to use D_{Coin 100}The payment to other users, whose owner is not the user 1, can not be completed, thereby preventing the repeated payment.

In the case of offline transactions, repeated payment checks are discovered and relied upon with lag, and at present, repeated payment checks performed by almost all electronic cash systems are delayed, i.e., they are performed after the payment process is completed.

Meanwhile, the transaction set by the user is a small payment (less than 1000 yuan), the transaction is an acceptable range for an individual user, and bad records are input into a credit system to be punished by adopting a posterior responsibility tracing mechanism.

In terms of convenience, a scheme (hereinafter referred to as a mobile phone scheme) of taking a mobile phone as a terminal carrier provides more implementation modes and use means, the system is convenient to deploy, the user operation convenience is good, and the popularization is easier.

In view of safety, the mobile phone is used as a D-RMB carrier, and HCE and TEE schemes can be adopted, so that a larger storage space is provided, a hardware manufacturer is not completely depended on, and the popularization is more convenient.

Compared with other currency systems replacing paper money in the market, the D-RMB has the characteristics of good convenience, high safety and the like, and the convenience is shown in the following aspects:

in the issuing mode, the D-RMB is the digitization of the currency, and does not depend on any bank account and a single network;

in the storage mode, the storage medium of the D-RMB can be a mobile phone, and can also be electronic equipment such as a card, a magnetic disk, a computer and the like, so that various choices are provided for a user. Especially, the D-RMB taking the mobile phone as a carrier can fully utilize the functions of the mobile phone, such as keyboard, display, positioning, storage, calculation, communication and the like, and can be developed for the second time, thereby greatly expanding the payment scene and convenience;

in the payment mode, the online payment transaction similar to paper money can be provided, the online remote payment transaction similar to an electronic payment system can also be provided, the online transaction and the offline transaction can be supported, and the mode is convenient and flexible;

the payment speed is greatly improved in the transaction speed compared with an online card swiping payment mode. Is very suitable for small amount quick payment;

in the use habit, the method can be compatible with the original card swiping payment mode, can also provide face-to-face digital currency payment, and can also provide electronic transaction records, thereby being convenient for financial statistics and having high user acceptability.

The safety is expressed in the following aspects:

in contrast to other digital currency systems, D-RMB digital currency is a series of electronic encrypted serial numbers converted from cash values, and payment transactions are completed through the transfer of these encrypted serial numbers. The safety of the currency is protected by a cryptographic algorithm, so that the confidentiality and the integrity of currency information can be effectively guaranteed, and the safety is high;

the safety of the D-RMB digital currency carrier realizes end-to-end safety by using a chip technology at a mobile terminal and a trusted technology at a background cloud;

the safety of the D-RMB digital currency transaction system depends on the traditional electronic payment system safety technology on one hand, and meanwhile, the strong D-RMB cloud computing system is utilized by the background to further guarantee the transaction safety;

in the aspect of user privacy protection, the user privacy is ensured and the risk of illegal transactions is avoided by means of 'foreground voluntary and background real name'.

The above-described embodiments should not be construed as limiting the scope of the invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions can occur, depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method of converting digital currency to physical cash, comprising:

the user terminal equipment selects equivalent digital currency in the digital currency wallet according to the cash amount input by external operation; the digital currency wallet is a client application installed on the user terminal device;

the user terminal device sends the digital currency to a commercial bank digital currency system;

the commercial bank digital currency system sending the digital currency to a central bank digital currency system;

the central bank digital currency system generates a one-time withdrawal code and then sends the one-time withdrawal code to the user terminal equipment to be presented to a user, and owner information of the digital currency is changed into a central bank by the user;

the commercial bank digital currency system sending the one-time withdrawal code provided by the user to the central bank digital currency system;

said central bank digital currency system confirming that said one-time withdrawal code is valid, then incrementing a commercial bank account by said cash redemption amount, and sending a notification to said commercial bank digital currency system that said one-time withdrawal code is valid;

and the commercial bank digital currency system sends a money supply instruction after receiving the notification, wherein the money supply instruction is used for controlling a machine or prompting a manual cash supply user to manually supply cash with the amount equal to the cash-out amount.

2. The method of converting digital currency to physical cash of claim 1, wherein the step of the commercial bank digital currency system sending the digital currency to a central bank digital currency system is preceded by the further step of:

the commercial bank digital currency system confirms that the digital currency is legal;

the commercial bank digital currency system confirming that the digital currency is equivalent to the cash converted amount;

the commercial bank digital currency system confirms that the user is a registered user of a commercial bank.

3. The method of converting digital currency into physical cash of claim 1, further comprising, prior to the step of the central bank digital currency system generating a one-time withdrawal code and then sending it to the user terminal device for presentation to the user:

the central bank digital currency system confirms that the owner of the digital currency is the user.

4. The method of converting digital currency into physical cash of claim 1, wherein the step of the central bank digital currency system altering the owner information of the digital currency from the user to the central bank is followed by further steps of:

the central bank digital currency system records the flow of transactions.

5. The method of converting digital currency into physical cash according to claim 1, wherein the step of the central bank digital currency system generating a one-time withdrawal code and then sending it to the user terminal device for presentation to the user comprises:

the central bank digital currency system generating redemption information including a one-time withdrawal code and then sending to the commercial bank digital currency system;

the commercial bank digital currency system forwards the redemption information to the user terminal device;

and the user terminal equipment extracts the one-time withdrawal code from the cashing information and then presents the one-time withdrawal code to the user.

6. A system for converting digital currency to physical cash, comprising: user terminal equipment, commercial bank digital currency system and central bank digital currency system, wherein:

the user terminal device is configured to: selecting equivalent digital currency in a digital currency wallet according to a cash amount input by external operation; sending the digital currency to the commercial bank digital currency system; the digital currency wallet is a client application installed on the user terminal device;

the commercial bank digital currency system is to: sending the digital currency to a central bank digital currency system; sending the user-provided one-time withdrawal code to the central bank digital currency system; sending a money supply instruction after a notice that the one-time withdrawal code is effective is sent, wherein the money supply instruction is used for controlling a machine or prompting a manual cash supply user to manually supply cash with the amount equal to the cash-out amount;

the central bank digital currency system is to: generating a one-time withdrawal code and then sending the one-time withdrawal code to the user terminal equipment to be presented to a user, and changing owner information of the digital currency into a central bank by the user; confirming that the one-time withdrawal code is valid, then adding the cash redemption amount to a commercial bank account, and sending a notification to the commercial bank digital currency system that the one-time withdrawal code is valid.

7. The system for converting digital currency to physical cash of claim 6, wherein the commercial bank digital currency system is further configured to:

confirming that the digital currency is legal;

confirming that the digital currency is equivalent to the converted cash amount;

confirming that the user is a registered user of the commercial bank.

8. The system for converting digital currency to physical cash according to claim 6, wherein the central bank digital currency system is further configured to:

confirming that the owner of the digital currency is the user.

9. The system for converting digital currency to physical cash according to claim 6, wherein the central bank digital currency system is further configured to: the transaction flow is recorded.

10. The system for converting digital currency into physical cash according to claim 6,

the central bank digital currency system is further configured to generate redemption information including a one-time withdrawal code and then send to the commercial bank digital currency system;

the commercial bank digital currency system is further used for forwarding the redemption information to the user terminal device; and

the user terminal equipment is also used for extracting a one-time withdrawal code from the cashing information and then presenting the one-time withdrawal code to the user.

11. A method of converting digital currency to physical cash, comprising:

the commercial bank digital currency system generates a one-time bank withdrawal code and sends the digital currency to a central bank digital currency system;

the central bank digital currency system changes owner information of the digital currency into a commercial bank by a user and then sends an owner updating success instruction to the commercial bank digital currency system;

the commercial bank digital currency system sends the disposable bank withdrawal code to the user terminal equipment according to the owner updating success instruction so as to present the disposable bank withdrawal code to the user;

the commercial bank digital currency system confirms that the one-time-use bank withdrawal code provided by the user is valid, and then issues a supply instruction, wherein the supply instruction is used for controlling a machine or prompting a person to manually pay cash with the amount equal to the cash-out amount.

12. The method of converting digital currency to physical cash of claim 11, further comprising, prior to the step of the commercial bank digital currency system sending the digital currency to a central bank digital currency system:

13. The method of converting digital currency to physical cash of claim 11, further comprising, prior to the step of the central bank digital currency system altering owner information of the digital currency from a user to a commercial bank:

14. The method of converting digital currency into physical cash of claim 11, wherein the step of the central bank digital currency system altering the owner information of the digital currency from a user to a commercial bank is followed by further comprising:

the central bank digital currency system records the flow of transactions.

15. A system for converting digital currency to physical cash, comprising: user terminal equipment, commercial bank digital currency system and central bank digital currency system, wherein:

the user terminal device is configured to: selecting equivalent digital currency in a digital currency wallet according to a cash amount input by external operation; sending the digital currency to a commercial bank digital currency system; the digital currency wallet is a client application installed on the user terminal device;

the commercial bank digital currency system is to: generating a disposable bank withdrawal code and sending the digital currency to a central bank digital currency system; according to the owner updating success instruction, sending the disposable bank withdrawal code to the user terminal equipment to be presented to the user; confirming that the disposable bank withdrawal code provided by the user is valid, and then sending a money supply instruction, wherein the money supply instruction is used for controlling a machine or prompting a user to manually pay cash with the amount equal to the cash-out amount;

the central bank digital currency system is to: and changing the owner information of the digital currency into a commercial bank by a user, and then sending an owner updating success instruction to the commercial bank digital currency system.

16. The system for converting digital currency to physical cash of claim 15, wherein the commercial bank digital currency system is further configured to:

confirming that the digital currency is legal;

confirming that the user is a registered user of the commercial bank.

17. The system for converting digital currency to physical cash according to claim 15, wherein the central bank digital currency system is further configured to:

confirming that the owner of the digital currency is the user.

18. The system for converting digital currency to physical cash according to claim 15, wherein the central bank digital currency system is further configured to: the transaction flow is recorded.