A method and system for instant confirmation of dual offline transactions based on digital certificates

Abstract

The present invention discloses a method and system for instant confirmation of dual offline transactions based on digital certificates, the method comprising using the digital certificate of the central bank to realize identity authentication between a commercial bank and the central bank; using the digital certificate of the sender's commercial bank to realize identity authentication between the sender user and the sender's commercial bank; using a pre-transaction method to realize the digital currency pre-transaction of the sender user; using a digital currency transaction method to instantly realize the digital currency transaction between the sender user and the receiver user; and using a pre-transaction rollback method to realize the rollback of the digital currency pre-transaction of the sender user. Beneficial effect: In the dual offline transaction scenario, the present invention can instantly confirm the transaction, thereby solving the problem that the payee cannot immediately use the received digital currency in the dual offline transaction, and at the same time eliminating the possibility that the payee receives invalid payment.

Description

Technical Field

[0001] The present invention relates to the field of computer communication technology, and in particular to a method and system for instant confirmation of dual offline transactions based on digital certificates. Background Art

[0002] With the development and popularization of mobile Internet, the mobile payment industry is undergoing rapid transformation and advancement. Business models based on various technologies such as mobile Internet, NFC, HCE, Token, and biometrics are constantly innovating, application scenarios are constantly expanding and enriching, and the integrated development of online and offline businesses is accelerating. While new mobile payment technologies provide users with diversified and convenient payment services, they also lead the transformation and upgrading of industries such as communications, finance, and the Internet. The digital economy is a product of the development of mobile Internet. Through the continuous upgrading of network infrastructure and information tools such as smart phones, Internet-cloud computing-blockchain-Internet of Things and other information technologies, the digital economy promotes the transformation of human economic forms from industrial economy to information economy-knowledge economy-smart economy. Therefore, the digital economy is an inevitable manifestation of the development of science and technology in an era. At the same time, the development of the digital economy has also led to the emergence of digital currency, which is also due to the development trend of the digital economy era.

[0003] Legal digital currency is an electronic currency represented by a series of character strings. It is issued by the central bank or authorized by the People's Bank of China, and is a legal currency in the form of an encrypted digital string representing a specific amount of money. Digital currency is built on the platform of today's mature computer technology and Internet technology. It is now issued or authorized by the central bank as the core system of digital currency and enters the circulation field. In the process of digital currency circulation, especially when it comes to offline circulation, it involves the transaction of digital currency. In the prior art, the transaction of digital currency is usually completed online in real time by the payee and the payee. Regarding the issue of how to quickly and effectively realize offline transactions of digital currency, this patent proposes a dual offline transaction instant confirmation method based on digital certificates in the field of digital currency circulation to achieve efficient offline digital currency transactions.

[0004] In the prior art, it is assumed that a payee A and a payee B conduct a digital currency transaction. The payee A now sends digital currency and the digital certificate of payee A to payee B, as well as the signature and encryption of the sent information completed by A, which is the transaction information; after receiving the transaction information, payee B verifies the validity of A's signature and the face value of the digital currency and forwards it to the commercial bank to which it belongs; the commercial bank verifies the transaction information and forwards it to the People's Bank of China; the People's Bank of China verifies the transaction information to confirm the transaction and records the flow information of the digital currency and then notifies the commercial bank of the transaction result; the commercial bank receives the transaction result to confirm the transaction and feedback to the payee B; B receives the transaction result and records the face value of the digital currency as its own face value of the digital currency. The above is the digital currency circulation completed by the payee and the payee based on online real-time in the prior art. Assuming that under certain limitations, for example, the payee A can be connected to the Internet, and the payee B cannot be connected to the Internet, then the payee B cannot obtain the transaction result immediately during the above transaction process, and can only continue to complete the transaction after connecting to the Internet.

[0005] Problems with existing technologies:

[0006] In the existing dual offline transactions of the digital currency of the People's Bank of China, the transfer of digital currency can be achieved through short-range communication. However, dual offline transactions have the following problems: the payee can only verify the received digital currency locally, and cannot obtain the certification of the People's Bank of China through the network, which results in the digital currency received cannot be used immediately, and can only be used after being connected to the Internet and certified by the People's Bank of China through the network; in addition, since the received digital currency cannot be immediately certified by the People's Bank of China, there is a certain risk of receiving payment, that is, the payee pays a double payment ("double spend") of digital currency, which results in the digital currency being unable to be subsequently certified by the People's Bank of China, and is an invalid payment. Summary of the invention

[0007] In view of the problems in the related art, the present invention proposes a method and system for instant confirmation of dual offline transactions based on digital certificates to overcome the above technical problems existing in the existing related art.

[0008] To this end, the specific technical solution adopted by the present invention is as follows:

[0009] According to one aspect of the present invention, a method for instant confirmation of dual offline transactions based on digital certificates is provided, the method comprising the following steps:

[0010] S1. Use the central bank’s digital certificate to achieve identity authentication between commercial banks and the central bank;

[0011] S2. Use the digital certificate of the sender's commercial bank to achieve identity authentication between the sender user and the sender's commercial bank;

[0012] S3. Use the pre-transaction method to implement the digital currency pre-transaction of the sender user;

[0013] S4. Using the digital currency transaction method to instantly realize the digital currency transaction between the sender user and the receiver user;

[0014] S5. Use the pre-transaction rollback method to implement the rollback of the digital currency pre-transaction of the sender user;

[0015] Wherein, the S1 specifically includes the following steps:

[0016] The receiving commercial bank and the sending commercial bank respectively obtain the digital certificate of the central bank, and the receiving commercial bank and the sending commercial bank use their respective digital certificates to perform identity authentication and session key negotiation with the central bank.

[0017] Furthermore, the method of identity authentication and session key negotiation in S1 is to use a digital certificate to perform HTTPS identity authentication to form a session key. After the session key is generated, subsequent communications all use this session key for confidential communication.

[0018] Furthermore, the use of the digital certificate of the sender's commercial bank in S2 to implement identity authentication between the sender user and the sender's commercial bank specifically includes the following steps:

[0019] The sender user obtains the digital certificate of the sender's commercial bank, and uses the digital certificate to perform HTTPS identity authentication with the sender's commercial bank and form a session key.

[0020] Furthermore, the use of the pre-transaction method in S3 to implement the digital currency pre-transaction of the sender user specifically includes the following steps:

[0021] S301, the sending user generates a first timestamp and transaction information, and signs and encrypts the first timestamp and transaction information to obtain first signature information, and generates first combination information and sends it to the sending commercial bank;

[0022] S302: After receiving the message, the sender commercial bank verifies the validity of the first timestamp, and after the verification is successful, sends the sender user digital certificate to the digital certificate issuing authority, and the digital certificate issuing authority verifies the digital certificate, and after the verification is successful, returns confirmation information to the sender commercial bank;

[0023] S303. After receiving the confirmation message, the commercial bank of the sending party confirms the identity of the trader by judging that the digital certificate is valid, and verifies the signature of the digital currency in the first signature information and the transaction information. After the verification is passed, the commercial bank of the sending party signs the first timestamp and the transaction information to obtain the second signature information, and generates the second combination information and sends it to the central bank;

[0024] S304. After receiving the message, the central bank verifies the validity of the first timestamp. After the verification is successful, the central bank sends the sender's user digital certificate to the digital certificate issuing authority. The digital certificate issuing authority verifies the sender's user digital certificate and returns confirmation information to the central bank after the verification is successful.

[0025] S305. After receiving the confirmation message, the central bank confirms the identity of the trader by judging whether the digital certificate is valid, and verifies the second signature information. After the verification is successful, the transaction information is verified. After the verification is successful, the result is recorded as the first result. The first result includes the validity period information of this pre-transaction. The central bank records the ownership change of the digital currency and the balance change of the transaction party after the transaction is successful.

[0026] S306. The central bank signs the first timestamp, the transaction information and the first result to obtain third signature information, generates third combination information and sends it to the recipient commercial bank;

[0027] S307. After receiving the message, the receiving commercial bank verifies the first timestamp, and verifies the third signature information and the signature of the digital currency in the transaction information. After the verification is successful, the result is recorded as the second result. The second result includes the information of the first result and the additional information of the receiving commercial bank on the transaction. At the same time, the first timestamp, transaction information and second result are recorded locally, and the ownership change of the digital currency and the balance change of the transaction party after the transaction is successful are recorded;

[0028] S308. The receiving commercial bank signs the first timestamp, the transaction information and the second result to obtain fourth signature information, generates fourth combination information and sends it to the central bank;

[0029] S309. After receiving the message, the central bank verifies the first timestamp, performs signature verification on the fourth signature information, and verifies the additional information of the receiving commercial bank in the second result. After the verification is passed, the central bank signs the first timestamp, the transaction information and the second result to obtain the fifth signature information, generates the fifth combination information and sends it to the sending commercial bank;

[0030] S310. After receiving the message, the commercial bank of the sender verifies the first timestamp and performs signature verification on the fifth signature information. After the verification is passed, the result is recorded as the third result. The third result includes the information of the second result and the additional information of the commercial bank of the sender on the transaction. The first timestamp, transaction information, the third result and the fifth signature information are saved locally as unfinished pre-transaction information, and the ownership change of the digital currency and the balance change of the transaction party after the transaction is successful are recorded. At the same time, the commercial bank of the sender signs the pre-transaction information to obtain the sixth signature information, and generates the sixth combination information and sends it to the sender user;

[0031] S311. After receiving the message, the sending user verifies the first timestamp and the sixth signature information. After the verification is passed, the pre-transaction information is saved locally.

[0032] Furthermore, the sender information in the method for generating the first combined information in S301 includes but is not limited to the sender user ID, the sender user wallet ID, contact information and hardware device code, and the recipient information includes but is not limited to the recipient user ID, the recipient user wallet ID, contact information and hardware device code.

[0033] Furthermore, the digital currency transaction between the sender user and the receiver user using the digital currency transaction method in S4 specifically includes the following steps:

[0034] S41, the sending user sends the pre-transaction information and the sending user's digital certificate to the receiving user via near field communication;

[0035] S42. After receiving the message, the receiving user verifies the digital certificate of the sending user to confirm the identity of the trader, and verifies the fifth signature information. After the verification is passed, the third result is confirmed. After confirmation, the receiving user takes out the digital currency from the transaction information and stores it, and the transaction is completed.

[0036] Furthermore, the near field communication method in S41 includes but is not limited to Bluetooth, wireless radio frequency technology and data cable.

[0037] Furthermore, the confirmation scope in S42 includes that the transaction is successful and that the transaction is within the validity period, and the additional information of the recipient's commercial bank and the sender's commercial bank in the third result is verified.

[0038] Furthermore, the use of the pre-transaction rollback method in S5 to implement the rollback of the digital currency pre-transaction of the sender user specifically includes the following steps:

[0039] S501: The sending user obtains the second timestamp, signs the pre-transaction information and the second timestamp to obtain the seventh signature information, generates the seventh combination information and sends it to the sending commercial bank;

[0040] S502: After receiving the message, the commercial bank of the sender verifies the validity of the second timestamp. After the verification is successful, the commercial bank of the sender sends the digital certificate of the user of the sender to the digital certificate issuing authority. The digital certificate issuing authority verifies the digital certificate of the user of the sender and returns confirmation information to the commercial bank of the sender after the verification is successful.

[0041] S503. After receiving the confirmation message, the commercial bank of the sending party confirms the identity of the trader by judging whether the digital certificate is valid, and verifies the seventh signature information. After the verification is passed, the commercial bank of the sending party signs the second timestamp and the pre-transaction information to obtain the eighth signature information, and generates the eighth combination information and sends it to the central bank.

[0042] S504. After receiving the message, the central bank verifies the validity of the second timestamp. After the verification is successful, the central bank sends the sender's user digital certificate to the digital certificate issuing authority. The digital certificate issuing authority verifies the sender's user digital certificate and returns confirmation information to the central bank after the verification is successful.

[0043] S505. After receiving the confirmation message, the central bank confirms the identity of the trader by judging whether the digital certificate is valid, and verifies the eighth signature information. After the verification is passed, the unfinished pre-transaction information is rolled back, and the result of successful rollback is recorded as the fourth result. The central bank records the ownership change of the digital currency and the balance change of the trading party after the pre-transaction information is rolled back.

[0044] S506. The central bank signs the composition message of the second timestamp, the pre-transaction information and the fourth result to obtain ninth signature information, generates ninth combination information and sends it to the receiving commercial bank;

[0045] S507. After receiving the message, the receiving commercial bank verifies the second timestamp and the ninth signature information. After the verification is passed, the result is recorded as the fifth result. The fifth result includes the information of the fourth result and the additional information of the receiving commercial bank on the transaction. The receiving commercial bank compares the unfinished pre-transaction information and the transaction information. If it is confirmed that they are related to the same transaction, the first timestamp, transaction information and second result previously saved locally are deleted, and the ownership change of the digital currency and the balance change of the transaction party after the pre-transaction information is rolled back are recorded.

[0046] S508. The receiving commercial bank signs the second timestamp, the pre-transaction information and the fifth result to obtain tenth signature information, generates tenth combination information and sends it to the central bank;

[0047] S509. After receiving the message, the central bank verifies the second timestamp, verifies the signature of the tenth signature information, and verifies the additional information of the receiving commercial bank in the fifth result. After the verification is passed, the central bank signs the second timestamp, the pre-transaction information and the fifth result to obtain the eleventh signature information, generates the eleventh combined information and sends it to the sending commercial bank;

[0048] S510. After receiving the eleventh combination information, the sending commercial bank verifies the second timestamp and performs signature verification on the eleventh signature information. After the verification is passed, the verification result is recorded as the sixth result. The sixth result includes the information of the fifth result and the additional information of the sending commercial bank on the transaction. At the same time, the receiving commercial bank rolls back the unfinished pre-transaction information and records the ownership change of the digital currency and the balance change of the transaction party after the transaction message is rolled back.

[0049] S511, the sending commercial bank signs the second timestamp, the pre-transaction information and the sixth result to obtain twelfth signature information, generates twelfth combination information and sends it to the sending user;

[0050] S512. After receiving the message, the sending user verifies the twelfth signature information and the additional information in RET_0. After the verification is passed, the pre-transaction information is deleted and the cancellation of the unfinished transaction is confirmed.

[0051] According to another aspect of the present invention, there is provided a dual offline transaction instant confirmation system based on digital certificates, the system comprising a central bank digital currency system, a commercial bank digital currency system, a user terminal digital currency system and a digital certificate issuing authority;

[0052] Among them, the commercial bank digital currency system includes the receiving commercial bank and the sending commercial bank, and the user terminal digital currency system includes the receiving user and the sending user. The receiving commercial bank corresponds to the receiving user, and the sending commercial bank corresponds to the sending user.

[0053] The central bank digital currency system is a digital currency issuing agency. The commercial bank digital currency system belongs to a digital currency issuing agency built at different levels together with the central bank. The digital certificate issuing agency issues digital certificates to users.

[0054] The beneficial effects of the present invention are as follows: in view of the payee's concerns about the validity of the received digital currency in a dual offline transaction scenario, the present invention designs a dual offline transaction instant confirmation method; the method forms a reliable unfinished transaction recognized by the central bank by the payee performing a digital currency pre-transaction in an online state; in the dual offline transaction scenario, the unfinished transaction is sent to the payee, and since the payee can verify the signature of the central bank, the transaction can be confirmed instantly, thereby verifying the digital currency received in the transaction, thereby solving the problem that the payee cannot immediately use the received digital currency in the dual offline transaction, and at the same time eliminating the possibility that the payee receives invalid payment. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 Schematic diagram of the instant confirmation method of dual offline transactions based on digital certificates;

[0057] Figure 2 Dual offline transaction instant confirmation method based on digital certificates, transaction rollback diagram. DETAILED DESCRIPTION

[0058] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0059] According to an embodiment of the present invention, a method and system for instant confirmation of dual offline transactions based on digital certificates are provided.

[0060] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. Figure 1-2 As shown, according to an embodiment of the present invention, a method for instant confirmation of dual offline transactions based on digital certificates is provided. In the implementation of the method, digital currency transactions are performed based on two user terminals, that is, there are a receiver and a sender, and the receiver and the sender are both offline during the transaction. The receiver is a user of Bank A, called receiver A1 (hereinafter referred to as "A1"), and the sender is a user of Bank B, called sender B1 (hereinafter referred to as "B1").

[0061] In the implementation manner of the present invention, the ID of the central bank is set to S, the ID of Bank A is set to IDA, and the ID of Bank B is set to IDB. The ID is a unique identifier of the bank digital currency system, usually representing identity information. The identifier is also located in the corresponding digital certificate and can be authenticated by the CA.

[0062] Specifically, the method comprises the following steps:

[0063] S1. Commercial bank A / B conducts identity authentication with the central bank (using the central bank's digital certificate to achieve identity authentication between commercial banks and the central bank)

[0064] A commercial bank (receiving commercial bank) and B commercial bank (sending commercial bank) obtain the central bank's digital certificate, and use the digital certificates they have obtained to conduct identity authentication and session key negotiation with the central bank. The method of identity authentication and session key negotiation includes: using a digital certificate to perform HTTPS identity authentication to form a session key. After the session key is generated, subsequent communications will use this session key for confidential communication.

[0065] S2, user B1 and commercial bank B conduct identity authentication (using the digital certificate of the sender's commercial bank to achieve identity authentication between the sender user and the sender's commercial bank)

[0066] Similarly, B1 (the sender user) obtains the digital certificate of B Company, and uses the digital certificate to perform HTTPS identity authentication with B Company to form a session key. After the session key is generated, the subsequent communications all use this session key for confidential communication.

[0067] S3. User B1 conducts digital currency pre-transaction (using the pre-transaction method to implement the digital currency pre-transaction of the sender user)

[0068] B1 generates signature information MSGB1=T||TX||CERTB1||SIGB1 (first combination information), and sends MSGB1 to B bank. The method for generating MSGB1 includes: B1 generates the current timestamp T (first timestamp) in pre-transaction; B1 combines the sender information, the receiver information, the digital currency, etc. into the transaction information TX; B1 uses the private key SKB1 to sign and encrypt the message composed of T and TX to obtain SIGB1=SIGN(T||TX, SKB1) (first signature information), and the private key SKB1 is the signature private key corresponding to the signature public key PKB1 in the digital certificate; B1 combines T, TX, SIGB1 and the digital certificate CERTB1 into the message MSGB1. The sender information in the method for generating MSGB1 includes: B1's ID, B1's wallet ID, contact information, hardware device code, etc. Similarly, the recipient information in the method of generating MSGB1 includes: A1 (receiver user) ID, A1's wallet ID, contact information, hardware device code, etc. Since A1 is an offline member, B1 needs to obtain it at the bank counter or through A1. The steps are as follows: Figure 1 shown.

[0069] B receives the MSGB1 message and verifies the validity of the timestamp T. After verification, it sends the digital certificate CERTB1 to the CA system. CA verifies CERTB1 and returns confirmation information to B after verification.

[0070] Bank B receives a confirmation message from CA that CERTB1 is valid, and determines that the digital certificate is valid, thereby confirming the identity of the trader. Bank B verifies the signature SIGB1 with the public key PKB1, and verifies the signature of the digital currency in TX with the central bank's public key. After the verification, Bank B uses its own private key SKB to sign T||TX to obtain SIGB1=SIGN(T||TX, SKB) (second signature information), where the private key SKB is the signature private key corresponding to the signature public key PKB in the digital certificate obtained by Bank B from CA. Bank B sends the message MSGB=T||TX||CERTB1||SIGB1 (second combination information) composed of T, TX, CERTB1, and SIGB1 to the central bank.

[0071] The central bank receives the MSGB message and verifies the validity of the timestamp T. After verification, it sends the digital certificate CERTB1 to the CA system. The CA verifies CERTB1 and returns confirmation information to the central bank after verification.

[0072] The central bank receives the confirmation message from CA that CERTB1 is valid, and determines that the digital certificate is valid, thereby confirming the identity of the trader. The central bank verifies the signature SIGB1 with the public key PKB, and verifies the transaction information TX after the verification is passed. After the verification is passed, the result is recorded as RETS (first result), and the RETS contains the validity period information of this pre-transaction. The central bank records the ownership changes of the digital currency and the balance changes of the trading parties after the transaction is successful.

[0073] The central bank uses its own private key SKS to sign the message composed of T, TX, and RETS to obtain SIGS1=SIGN(T||TX||RETS, SKS) (third signature information). The private key SKS is the signature private key corresponding to the signature public key PKS in the digital certificate issued by the CA to the central bank. The central bank sends the message composed of T, TX, RETS, and SIGS1, MSGS1=T||TX||RETS||SIGS1 (third combination information), to Bank A.

[0074] After receiving MSGS1, Commercial Bank A verifies the timestamp T. Commercial Bank A uses the public key PKS to verify the signature SIGS1, and uses the central bank's public key to verify the signature of the digital currency in TX. After the verification is passed, the result is recorded as RETA (second result). RETA contains the information of RETS and A's additional information on the transaction. The additional information can be A's evaluation, conclusion, and supporting materials on the transaction, and carries A's digital signature. Commercial Bank A records T||TX||RETA locally, and records the changes in the ownership of the digital currency and the balance changes of the transaction parties after the transaction is successful.

[0075] A uses its own private key SKA to sign T||TX||RETA to obtain SIGA=SIGN(T||TX||RETA,SKA)(the fourth signature information), where the private key SKA is the signature private key corresponding to the signature public key PKA in the digital certificate obtained by A from CA. A sends the message MSGA=T||TX||RETA||SIGA (the fourth combination information) composed of T, TX, RETA and SIGA to the central bank.

[0076] The central bank receives MSGA and verifies the timestamp T. The central bank uses the public key PKA to sign SIGA and passes the verification of the additional information of A in RETA. After the verification, the central bank uses its own private key SKS to sign T||TX||RETA to obtain SIGS2=SIGN(T||TX||RETA,SKS)(fifth signature information). The central bank sends the message MSGS2=T||TX||RETA||SIGS2 (fifth combination information) composed of T, TX, RETA, and SIGS2 to Bank B.

[0077] B Merchant receives the MSGS2 verification timestamp T, and uses the public key PKS to perform signature verification on SIGS2. After verification, the verification result is recorded as RETB (third result). RETB contains the information of RETA and B's additional information on the transaction. The additional information can be B's evaluation, conclusion, and supporting materials on the transaction, and carries B's digital signature. B Merchant saves T||TX||RETB||SIGS2 as unfinished pre-transaction information UTX=T||TX||RETB||SIGS2 locally, and records the ownership change of digital currency and the balance change of the transaction party after the transaction is successful. B Merchant uses its own private key SKB to sign UTX to obtain SIGB2=SIGN(UTX,SKB) (sixth signature information), and B Merchant composes the information UTX||SIGB2 and sends it to B1 (sixth combination information).

[0078] After B1 receives UTX||SIGB2, it verifies the timestamp T and uses the public key PKB to verify SIGB2. After verification, the pre-transaction information UTX is saved locally.

[0079] S4. User B1 conducts digital currency transactions with user A1 (using the digital currency transaction method to instantly realize the digital currency transaction between the sender user and the receiver user)

[0080] B1 sends UTX||CERTB1 to A1 via near field communication, which includes Bluetooth, wireless radio frequency technology, data cable and other technology communication technologies.

[0081] After A1 receives UTX||CERTB1, it uses the CA public key to verify CERTB1 to confirm the identity of the trader, and uses the public key PKS to verify SIGS2. After the verification, RETB is confirmed. If RETB contains a successful transaction and the transaction is within the validity period, and the additional information of A and B in RETB is verified, A1 takes out the digital currency from TX and stores it, and the transaction is completed. Since A1 has obtained the approval signatures of the central bank, Bank A, and Bank B for the transaction, the dual offline transaction can be completed instantly without going online to confirm with the central bank, Bank A, and Bank B. At the same time, A1 can use the received digital currency immediately.

[0082] S5. User B1 rolls back the digital currency pre-transaction (using the pre-transaction rollback method to roll back the digital currency pre-transaction of the sender user)

[0083] Before B1 and A1 conduct digital currency transactions, they abandon the pre-transaction for various reasons. The reasons for abandonment can be: the expiration of the pre-transaction, the active abandonment of the transaction with the recipient A1, the expiration of the digital certificate of the party, the expiration of the digital certificate of the recipient, etc. Therefore, B1 needs to actively initiate a rollback application for the pre-transaction. The steps are as follows: Figure 2 shown.

[0084] Before temporarily abandoning the transaction, B1 obtains the current timestamp T0 (second timestamp). B1 uses its own private key SKB1 to sign UTX||T0 to obtain SIGB10=(T0||UTX, SKB1) (seventh signature information). B1 generates signature information MSGB10=UTX||CERTB1||SIGB10||T0 (seventh combination information). And sends MSGB10 to B Bank.

[0085] B receives the MSGB10 message and verifies the validity of the timestamp T0. After verification, it sends the digital certificate CERTB1 to the CA system. CA verifies CERTB1 and returns confirmation information to B after verification.

[0086] B receives the confirmation message from CA that CERTB1 is valid, and determines that the digital certificate is valid, thereby confirming the identity of the trader. B verifies the signature SIGB10 with the public key PKB1. After the verification is passed, B uses its own private SKB to sign T0||UTX to obtain SIGB10. 0-1 =SIGN(T0||UTX,SKB)(eighth signature information), Bank B will convert T0, UTX, CERTB1, SIGB 0-1 Message MSGB0 = T0||UTX||CERTB1||SIGB 0-1 (The eighth combination of information) is sent to the central bank.

[0087] The central bank receives the MSGB0 message and verifies the validity of the timestamp T0. After the verification is successful, it sends the digital certificate CERTB1 to the CA system. The CA verifies CERTB1 and returns confirmation information to the central bank after the verification is successful.

[0088] The central bank receives the confirmation message from the CA that the CERTB1 verification is valid, and determines that the digital certificate is valid, thereby confirming the identity of the trader. The central bank uses the public key PKB to verify the signature SIGB 0-1 After verification, the unfinished pre-transaction UTX is rolled back, and the result of successful rollback is recorded as RETS0 (the fourth result). The central bank records the changes in the ownership of digital currency and the balance changes of the transaction parties after the UTX is rolled back.

[0089] The central bank uses its own private key SKS to sign the composition message of T0, UTX, and RETS0 to obtain SIGS 0-1 =SIGN(T0||UTX||RETS0,SKS)(9th signature information). The central bank will T0, UTX, RETS0, SIGS 0-1 Composition message MSGS 0-1 =T0||UTX||RETS0||SIGS 0-1 (Ninth combination of information) is sent to Bank A.

[0090] A Company received MSGS 0-1 After that, the timestamp T0 is verified. Bank A obtains the public key PKS to verify the signature SIGS 0-1 After verification, the result is recorded as RETA0 (fifth result). RETA0 contains the information of RETS0 and A's additional information on the transaction. The additional information can be A's evaluation, conclusion, and supporting materials on the transaction, and carries A's digital signature. Bank A compares the received unfinished pre-transaction UTX with the previously stored transaction TX. If it is confirmed that they are related to the same transaction, the previously saved record T||TX||RETA is deleted. A records the ownership changes of digital currency and the balance changes of the transaction parties after UTX is rolled back.

[0091] A commercial bank uses its own private key SKA to sign T0||UTX||RETA0 to obtain SIGA0=SIGN(T0||UTX||RETA0,SKA)(the tenth signature information). A commercial bank sends the message MSGA0=T0||UTX||RETA0||SIGA0 (the tenth combination information) composed of T0, UTX, RETA0 and SIGA0 to the central bank.

[0092] The central bank receives MSGA0 and verifies the timestamp T0. The central bank uses the public key PKA to verify the signature of SIGA0, and the additional information of A in RETA0 is verified. After the verification, the central bank uses its own private key SKS to sign T0||UTX||RETA0 to obtain SIGS 0-2 =SIGN(T0||UTX||RETA0,SKS)(11th signature information). The central bank will T0, UTX, RETA0, SIGS 0-2 Composition message MSGS 0-2 =T0||UTX||RETA0||SIGS 0-2 (The eleventh combination of information) is sent to Company B.

[0093] B Company received MSGS 0-2 Verify timestamp T0, B bank takes public key PKS to SIGS 0-2Signature verification is performed, and after verification, the verification result is recorded as RETB0 (sixth result). RETB0 contains the information of RETA0 and B's additional information on the transaction. The additional information can be B's evaluation, conclusion, and supporting materials on the transaction, and carries B's digital signature. B rolls back the unfinished pre-transaction UTX and records the ownership changes of the digital currency and the balance changes of the transaction parties after the UTX is rolled back.

[0094] B will use its private key SKB to sign T0||UTX||RETB0 to obtain SIGB 0-2 =SIGN(T0||UTX||RETB0,SKB)(12th signature information), B bank composition information T0||UTX||RETB0||SIGB 0-2 (Twelfth combination information) is sent to B1.

[0095] B1 receives T0||UTX||RETB0||SIGB 0-2 After that, take the public key PKB to SIGB 0-2 Verify, and the additional information of A and B in RETB0 is verified. After verification, delete the pre-transaction UTX and confirm the cancellation of the unfinished transaction.

[0096] According to another aspect of the present invention, a dual offline transaction instant confirmation system based on digital certificates is provided; the system includes a central bank digital currency system, a commercial bank digital currency system, a user terminal digital currency system and a digital certificate issuing authority. The central bank digital currency system is a digital currency issuing authority, which has transaction functions such as digital currency issuance, registration, and change; the commercial bank digital currency system belongs to a digital currency issuing authority built together with the central bank in a hierarchical manner, and can be a number of commercial bank digital currency systems in actual implementation; the user terminal digital currency system includes POS machines, mobile phones, NFC or other devices equipped with bank-authorized digital currency transaction software, etc.; the digital certificate issuing authority is usually a digital certificate authorization center service system built by the central bank or a commercial bank authorized by the central bank, or a digital certificate authorization center service system authorized by the government, which issues digital certificates to users for identity authentication during digital currency transactions.

[0097] In summary, the present invention designs a method for instant confirmation of dual offline transactions in response to the payee's concerns about the validity of the received digital currency in a dual offline transaction scenario; this method requires the payee to conduct a digital currency pre-transaction in an online state to form a reliable unfinished transaction recognized by the central bank; in the dual offline transaction scenario, the unfinished transaction is sent to the payee, and since the payee can verify the signature of the central bank, the transaction can be confirmed instantly, thereby verifying the digital currency received in the transaction, thereby solving the problem that the payee cannot immediately use the received digital currency in the dual offline transaction, and at the same time eliminating the possibility that the payee receives invalid payment.

[0098] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0099] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for instant confirmation of dual offline transactions based on digital certificates, characterized in that: The method comprises the following steps: S1. Use the central bank’s digital certificate to achieve identity authentication between commercial banks and the central bank; S2. Use the digital certificate of the sender's commercial bank to achieve identity authentication between the sender user and the sender's commercial bank; S3. Use the pre-transaction method to implement the digital currency pre-transaction of the sender user; S4. Using the digital currency transaction method to instantly realize the digital currency transaction between the sender user and the receiver user; S5. Use the pre-transaction rollback method to implement the rollback of the digital currency pre-transaction of the sender user; Wherein, S1 specifically includes the following steps: the receiving commercial bank and the sending commercial bank respectively obtain the digital certificate of the central bank, and the receiving commercial bank and the sending commercial bank use their respective obtained digital certificates to perform identity authentication and session key negotiation with the central bank; The use of the pre-transaction method in S3 to implement the digital currency pre-transaction of the sender user specifically includes the following steps: S301, the sending user generates a first timestamp and transaction information, and signs and encrypts the first timestamp and transaction information to obtain first signature information, and generates first combination information and sends it to the sending commercial bank; S302: After receiving the message, the sender commercial bank verifies the validity of the first timestamp, and after the verification is successful, sends the sender user digital certificate to the digital certificate issuing authority, and the digital certificate issuing authority verifies the digital certificate, and after the verification is successful, returns confirmation information to the sender commercial bank; S303. After receiving the confirmation message, the commercial bank of the sending party confirms the identity of the trader by judging that the digital certificate is valid, and verifies the signature of the digital currency in the first signature information and the transaction information. After the verification is passed, the commercial bank of the sending party signs the first timestamp and the transaction information to obtain the second signature information, and generates the second combination information and sends it to the central bank; S304. After receiving the message, the central bank verifies the validity of the first timestamp. After the verification is successful, the central bank sends the sender's user digital certificate to the digital certificate issuing authority. The digital certificate issuing authority verifies the sender's user digital certificate and returns confirmation information to the central bank after the verification is successful. S305. After receiving the confirmation message, the central bank confirms the identity of the trader by judging whether the digital certificate is valid, and verifies the second signature information. After the verification is successful, the transaction information is verified. After the verification is successful, the result is recorded as the first result. The first result includes the validity period information of this pre-transaction. The central bank records the ownership change of the digital currency and the balance change of the transaction party after the transaction is successful. S306. The central bank signs the first timestamp, the transaction information and the first result to obtain third signature information, generates third combination information and sends it to the receiving commercial bank; S307. After receiving the message, the receiving commercial bank verifies the first timestamp, and verifies the third signature information and the signature of the digital currency in the transaction information. After the verification is successful, the result is recorded as the second result. The second result includes the information of the first result and the additional information of the receiving commercial bank on the transaction. At the same time, the first timestamp, transaction information and second result are recorded locally, and the ownership change of the digital currency and the balance change of the transaction party after the transaction is successful are recorded; S308. The receiving commercial bank signs the first timestamp, the transaction information and the second result to obtain fourth signature information, generates fourth combination information and sends it to the central bank; S309. After receiving the message, the central bank verifies the first timestamp, performs signature verification on the fourth signature information, and verifies the additional information of the receiving commercial bank in the second result. After the verification is passed, the central bank signs the first timestamp, the transaction information and the second result to obtain the fifth signature information, generates the fifth combination information and sends it to the sending commercial bank; S310. After receiving the message, the commercial bank of the sender verifies the first timestamp and performs signature verification on the fifth signature information. After the verification is passed, the result is recorded as the third result. The third result includes the information of the second result and the additional information of the commercial bank of the sender on the transaction. The first timestamp, transaction information, the third result and the fifth signature information are saved locally as unfinished pre-transaction information, and the ownership change of the digital currency and the balance change of the transaction party after the transaction is successful are recorded. At the same time, the commercial bank of the sender signs the pre-transaction information to obtain the sixth signature information, and generates the sixth combination information and sends it to the sender user; S311. After receiving the message, the sending user verifies the first timestamp and the sixth signature information. After the verification is passed, the pre-transaction information is saved locally.

2. A method for instant confirmation of dual offline transactions based on digital certificates according to claim 1, characterized in that: The method of identity authentication and session key negotiation in S1 is to use a digital certificate to perform HTTPS identity authentication to form a session key. After the session key is generated, subsequent communications all use this session key for confidential communication.

3. A method for instant confirmation of dual offline transactions based on digital certificates according to claim 1, characterized in that: The use of the digital certificate of the sender's commercial bank in S2 to implement identity authentication between the sender user and the sender's commercial bank specifically includes the following steps: The sender user obtains the digital certificate of the sender's commercial bank, and uses the digital certificate to perform HTTPS identity authentication with the sender's commercial bank and form a session key.

4. A method for instant confirmation of dual offline transactions based on digital certificates according to claim 1, characterized in that: The sender information in the method for generating the first combined information in S301 includes but is not limited to the sender user ID, the sender user wallet ID, contact information and hardware device code, and the receiver information includes but is not limited to the receiver user ID, the receiver user wallet ID, contact information and hardware device code.

5. A method for instant confirmation of dual offline transactions based on digital certificates according to claim 1, characterized in that: The S4 specifically comprises the following steps: S41, the sending user sends the pre-transaction information and the sending user's digital certificate to the receiving user via near field communication; S42. After receiving the message, the receiving user verifies the digital certificate of the sending user to confirm the identity of the trader, and verifies the fifth signature information. After the verification is passed, the third result is confirmed. After confirmation, the receiving user takes out the digital currency from the transaction information and stores it, and the transaction is completed.

6. A method for instant confirmation of dual offline transactions based on digital certificates according to claim 5, characterized in that: The near field communication method in S41 includes but is not limited to Bluetooth, wireless radio frequency technology and data cable.

7. A method for instant confirmation of dual offline transactions based on digital certificates according to claim 5, characterized in that: The confirmation scope in S42 includes that the transaction is successful and that the transaction is within the validity period, and the additional information of the recipient's commercial bank and the sender's commercial bank in the third result is verified.

8. A method for instant confirmation of dual offline transactions based on digital certificates according to claim 1, characterized in that: The method of implementing the rollback of the digital currency pre-transaction of the sender user by using the pre-transaction rollback method in S5 specifically includes the following steps: S501: The sending user obtains the second timestamp, signs the pre-transaction information and the second timestamp to obtain the seventh signature information, generates the seventh combination information and sends it to the sending commercial bank; S502: After receiving the message, the commercial bank of the sender verifies the validity of the second timestamp. After the verification is successful, the commercial bank of the sender sends the digital certificate of the user of the sender to the digital certificate issuing authority. The digital certificate issuing authority verifies the digital certificate of the user of the sender and returns confirmation information to the commercial bank of the sender after the verification is successful. S503. After receiving the confirmation message, the commercial bank of the sending party confirms the identity of the trader by judging whether the digital certificate is valid, and verifies the seventh signature information. After the verification is passed, the commercial bank of the sending party signs the second timestamp and the pre-transaction information to obtain the eighth signature information, and generates the eighth combination information and sends it to the central bank. S504. After receiving the message, the central bank verifies the validity of the second timestamp. After the verification is successful, the central bank sends the sender's user digital certificate to the digital certificate issuing authority. The digital certificate issuing authority verifies the sender's user digital certificate and returns confirmation information to the central bank after the verification is successful. S505. After receiving the confirmation message, the central bank confirms the identity of the trader by judging whether the digital certificate is valid, and verifies the eighth signature information. After the verification is passed, the unfinished pre-transaction information is rolled back, and the result of successful rollback is recorded as the fourth result. The central bank records the ownership change of the digital currency and the balance change of the trading party after the pre-transaction information is rolled back. S506. The central bank signs the composition message of the second timestamp, the pre-transaction information and the fourth result to obtain ninth signature information, and generates ninth combination information and sends it to the receiving commercial bank; S507. After receiving the message, the receiving commercial bank verifies the second timestamp and the ninth signature information. After the verification is passed, the result is recorded as the fifth result. The fifth result includes the information of the fourth result and the additional information of the receiving commercial bank on the transaction. The receiving commercial bank compares the unfinished pre-transaction information and the transaction information. If it is confirmed that they are related to the same transaction, the first timestamp, transaction information and second result previously saved locally are deleted, and the ownership change of the digital currency and the balance change of the transaction party after the pre-transaction information is rolled back are recorded. S508. The receiving commercial bank signs the second timestamp, the pre-transaction information and the fifth result to obtain tenth signature information, generates tenth combination information and sends it to the central bank; S509. After receiving the message, the central bank verifies the second timestamp, verifies the signature of the tenth signature information, and verifies the additional information of the receiving commercial bank in the fifth result. After the verification is passed, the central bank signs the second timestamp, the pre-transaction information and the fifth result to obtain the eleventh signature information, generates the eleventh combined information and sends it to the sending commercial bank; S510. After receiving the eleventh combination information, the sending commercial bank verifies the second timestamp and performs signature verification on the eleventh signature information. After the verification is passed, the verification result is recorded as the sixth result. The sixth result includes the information of the fifth result and the additional information of the sending commercial bank on the transaction. At the same time, the receiving commercial bank rolls back the unfinished pre-transaction information and records the ownership change of the digital currency and the balance change of the transaction party after the transaction message is rolled back. S511, the sending commercial bank signs the second timestamp, the pre-transaction information and the sixth result to obtain twelfth signature information, generates twelfth combination information and sends it to the sending user; S512. After receiving the message, the sending user verifies the twelfth signature information and the additional information in the sixth result. After the verification is passed, the pre-transaction information is deleted to confirm the cancellation of the unfinished transaction.

9. A system for instant confirmation of dual offline transactions based on digital certificates, used to implement the steps of the method for instant confirmation of dual offline transactions based on digital certificates as described in any one of claims 1 to 8, characterized in that: The system includes a central bank digital currency system, a commercial bank digital currency system, a user terminal digital currency system and a digital certificate issuing authority; wherein, the commercial bank digital currency system includes a receiving commercial bank and a sending commercial bank, the user terminal digital currency system includes a receiving user and a sending user, the receiving commercial bank corresponds to the receiving user, and the sending commercial bank corresponds to the sending user; the central bank digital currency system is a digital currency issuing agency, and the commercial bank digital currency system belongs to a digital currency issuing agency built at different levels together with the central bank, and the digital certificate issuing authority issues digital certificates to users.

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