Inter-bank collection asset verification method and device, and computer readable storage medium

Abstract

The invention provides an inter-bank collection asset verification method and apparatus, and a computer readable storage medium. The method comprises the steps of controlling a registration center to generate a symmetric homomorphic key and sending the symmetric homomorphic key to an initiating bank and all response banks; the initiating bank sends an inter-bank asset verification request to the authority, so that the authority randomly selects a chaos factor and sends the chaos factor to the initiating bank and the target response bank; the target response bank is controlled to generate a ciphertext report according to the bank asset data of the target customer and send the ciphertext report to the authority; the control authority generates an aggregation report according to all the ciphertext reports and submits the aggregation report to the initiating bank; and the initiating bank decrypts according to the aggregation report to obtain decrypted asset data and compares the decrypted asset data with the current overdue asset data of the target customer for judgment. According to the method and the device, the problem that in the prior art, mutual trust between every two banks is difficult to realize, the risk of customer data inter-bank privacy leakage exists, and the banks cannot know all asset conditions of the target customer, so that effective inter-bank asset collection cannot be carried out is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of inter-bank debt collection, and in particular to an inter-bank debt collection asset verification method, an inter-bank debt collection asset verification device, a computer-readable storage medium and an inter-bank debt collection asset verification system. Background Art

[0002] The collection business plays a vital role in the post-loan management of banks and is directly related to the bank's loan recovery and risk management. Effective collection can reduce the number of non-performing assets (such as bad debts and doubtful debts) and help maintain the asset quality and capital adequacy of banks. Banks need to take a variety of measures to encourage customers to repay their debts as soon as possible when their loans or credit cards are overdue. However, there are some special circumstances that make cross-bank deductions impractical. For example, some customers may have recognized that the deduction operation of a certain bank is usually performed in the morning every day, and they will quickly transfer funds to other bank accounts after receiving their wages in the afternoon, making it impossible to perform deductions in this bank. Or, the customer's salary card may originally belong to another bank, and the bank's card has no repayment mechanism associated with the overdue account, resulting in the customer having deposits in other banks but not repaying the overdue debts of this bank.

[0003] The above scenario illustrates the challenges of interbank deductions. Direct interbank deductions are limited by privacy, regulatory and compliance requirements and therefore cannot be implemented directly. Although interbank deductions cannot be implemented, one of the prerequisites for interbank deductions is to determine whether a delinquent customer has sufficient assets among all banks. Only after obtaining this information can the next step of collection action be taken, such as court litigation to enforce interbank deductions. Currently, there are almost no feasible interbank deduction methods. According to the existing deduction ideas, multiple banks need to authorize each other. This approach still has the following disadvantages: (1) The procedures are complicated and redundant, and mutual trust between multiple banks is difficult to achieve and does not meet compliance requirements; (2) There is a risk of cross-bank privacy leakage of customer data, and personal data is not easy to control in a refined manner. Summary of the invention

[0004] The main purpose of the present application is to provide an inter-bank asset collection verification method, an inter-bank asset collection verification device, a computer-readable storage medium and an inter-bank asset collection verification system, so as to at least solve the problem in the prior art that mutual trust between multiple banks is difficult to achieve and there is a risk of cross-bank privacy leakage of customer data, so that banks cannot know all the asset situations of the target customers, resulting in the inability to conduct effective inter-bank asset collection.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a cross-bank collection asset verification method is provided, including: controlling a registration center to generate a symmetric homomorphic key, and sending the symmetric homomorphic key to an initiating bank and all responding banks, the registration center is used to initialize the key, the initiating bank is a bank that initiates an inter-bank asset verification request, the responding bank is a bank that has signed an inter-bank collection asset verification agreement other than the initiating bank, the inter-bank asset verification request is used to apply to view the cross-bank asset status of a target customer, the inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data; the initiating bank sends the inter-bank asset verification request to an authority so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target responding bank, and the target responding bank is a bank that owns the target customer. The responding bank; controls the target responding bank to calculate the ciphertext according to the symmetric homomorphic key based on the bank asset data of the target customer, generates a corresponding ciphertext report and sends the ciphertext report to the authoritative institution, wherein the bank asset data is the asset data of the target customer in the corresponding target responding bank, and one target responding bank generates one ciphertext report; controls the authoritative institution to calculate the aggregated ciphertext according to all the ciphertext reports, generates an aggregated report and submits the aggregated report to the initiating bank; the initiating bank decrypts according to the aggregated report to obtain the decrypted asset data, and compares and judges the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer according to the judgment result and execute the corresponding asset collection plan, wherein the current overdue asset data is the overdue asset situation of the target customer in the initiating bank.

[0006] Optionally, controlling a registration center to generate a symmetric homomorphic key includes: controlling the registration center to select a first prime number, a second prime number, a first random parameter, and a ciphertext level, and calculating a public parameter based on the product of the first prime number and the second prime number, the first prime number being greater than the second prime number; and generating the symmetric homomorphic key based on the second prime number, the first random parameter, and the ciphertext level.

[0007] Optionally, the initiating bank sends the inter-bank asset verification request to the authority, so that the authority randomly selects the chaos factor and sends the chaos factor to the initiating bank and the target response bank, including: the initiating bank sends the inter-bank asset verification request to the authority to apply to view the inter-bank asset status of the target customer, so that the authority queries the corresponding response bank according to the inter-bank asset verification request to obtain the target response bank; controls the authority to randomly select the chaos factor k i, and sends the chaotic factor to the corresponding response bank, the chaotic factor satisfies k1+k2+…+k i +…+k n =0 mod N.

[0008] Optionally, controlling the registration center to select a first prime number, a second prime number, a first random parameter, and a ciphertext level, and calculating a public parameter according to the product of the first prime number and the second prime number, controlling the target response bank to calculate a ciphertext according to the symmetric homomorphic key based on the bank asset data of the target customer, generating a corresponding ciphertext report and sending the ciphertext report to the authority, including: controlling the target response bank to obtain a plaintext according to the bank asset data of the target customer in its own bank, and selecting a second random parameter, the sum of the absolute value of the second random parameter and the absolute value of the second prime number is less than the absolute value of the public parameter; controlling the target response bank to calculate a ciphertext according to a first formula using the symmetric homomorphic key and the plaintext, the first formula being C i =s d (r i q+m i +k i )mod N,C i represents the ciphertext of the i-th target response bank, s represents the first random parameter, d represents the ciphertext level, r i represents the second random parameter selected by the i-th target response bank, m i represents the plaintext obtained by the i-th target response bank, k i represents the chaos factor sent to the i-th target response bank, N represents the public parameter; controls the target response bank to generate the ciphertext report according to the ciphertext, and sends the ciphertext report to the authority, wherein the ciphertext report includes the current timestamp, the ciphertext and the identity of the target response bank.

[0009] Optionally, controlling the authoritative institution to calculate the aggregated ciphertext according to all the ciphertext reports, generate an aggregated report and submit the aggregated report to the initiating bank includes: controlling the authoritative institution to receive all the ciphertext reports and calculate the aggregated ciphertext according to a second formula, wherein the second formula is C=C1+C2+…+C i +…+C n mod N,C i represents the ciphertext of the i-th target response bank, and C represents the aggregated ciphertext; controls the authoritative agency to generate the aggregated report according to the aggregated ciphertext, and sends the aggregated report to the initiating bank, wherein the ciphertext report includes the current timestamp, the aggregated ciphertext and the identity of the authoritative agency.

[0010] Optionally, the judgment result is that the target customer has fully repayable assets, or the target customer has partially repayable assets, or the target customer has no assets, the fully repayable assets mean that the total assets of the target customer in all the target response banks can repay all the debts owed to the initiating bank, and the partially repayable assets mean that the total assets of the target customer in all the target response banks cannot fully repay all the debts owed to the initiating bank, the initiating bank decrypts according to the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain the judgment result, including: the initiating bank receives the authority's After receiving the aggregation report sent by the structure, the aggregation report is decrypted using the homomorphic encryption key and a symmetric homomorphic encryption algorithm to obtain the decrypted asset data; the decrypted asset data is compared with the current overdue asset data; when the decrypted asset data is greater than or equal to the current overdue asset data, it is determined that the judgment result is that the target customer has the fully repayable assets; when the decrypted asset data is less than the current overdue asset data and the decrypted asset data is greater than zero, it is determined that the judgment result is that the target customer has partially repayable assets; when the decrypted asset data is less than or equal to zero, it is determined that the judgment result is that the target customer has no assets.

[0011] Optionally, after the initiating bank decrypts the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the target customer's current overdue asset data to obtain a judgment result, the method further includes: when the judgment result is that the target customer has fully repayable assets or the judgment result is that the target customer has partially repayable assets, determining that the asset collection plan is to execute inter-bank deductions through court litigation.

[0012] According to another aspect of the present application, there is provided an inter-bank collection asset verification device, the device comprising: a first control unit, used to control a registration center to generate a symmetric homomorphic key, and send the symmetric homomorphic key to an initiating bank and all responding banks, the registration center is used to initialize the key, the initiating bank is a bank that initiates an inter-bank asset verification request, the responding bank is a bank that has signed an inter-bank collection asset verification agreement other than the initiating bank, the inter-bank asset verification request is used to apply to view the inter-bank asset status of a target customer, the inter-bank collection asset verification agreement is an agreement for sharing asset data to verify customer assets under the premise of ensuring the privacy of bank customer data; an initiating unit, used for the initiating bank to send the inter-bank asset verification request to an authority, so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target responding bank, the target responding bank is the responding bank that owns the target customer; A second control unit is used to control the target response bank to calculate the ciphertext based on the bank asset data of the target customer according to the symmetric homomorphic key, generate a corresponding ciphertext report and send the ciphertext report to the authoritative institution, wherein the bank asset data is the asset data of the target customer in the corresponding target response bank, and one target response bank generates one ciphertext report; a third control unit is used to control the authoritative institution to calculate the aggregated ciphertext according to all the ciphertext reports, generate an aggregated report and submit the aggregated report to the initiating bank; a decryption unit is used for the initiating bank to decrypt according to the aggregated report to obtain the decrypted asset data, and compare and judge the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer according to the judgment result and execute the corresponding asset collection plan, wherein the current overdue asset data is the overdue asset situation of the target customer in the initiating bank.

[0013] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute any one of the methods described.

[0014] According to another aspect of the present application, an inter-bank collection asset verification system is provided, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include methods for executing any one of the described methods.

[0015] Applying the technical solution of the present application, in the inter-bank collection asset verification method, first, the control registration center generates a symmetric homomorphic key, and sends the above-mentioned symmetric homomorphic key to the initiating bank and all the responding banks, the above-mentioned registration center is used to initialize the key, the above-mentioned initiating bank is the bank that initiates the inter-bank asset verification request, the above-mentioned responding bank is the bank that signs and participates in the inter-bank collection asset verification agreement other than the above-mentioned initiating bank, the above-mentioned inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer, and the above-mentioned inter-bank collection asset verification agreement is an agreement for sharing asset data to verify customer assets under the premise of ensuring the privacy of bank customer data; then, the above-mentioned initiating bank sends the above-mentioned inter-bank asset verification request to an authority, so that the above-mentioned authority randomly selects a chaotic factor and sends the above-mentioned chaotic factor to the above-mentioned initiating bank and the target responding bank, and the above-mentioned target responding bank is the above-mentioned responding bank that owns the above-mentioned target customer; after that , control the above-mentioned target response bank to calculate the ciphertext based on the bank asset data of the above-mentioned target customer according to the above-mentioned symmetric homomorphic key, generate the corresponding ciphertext report and send the above-mentioned ciphertext report to the above-mentioned authoritative institution, the above-mentioned bank asset data is the asset data of the above-mentioned target customer in the corresponding above-mentioned target response bank, and one above-mentioned target response bank generates one above-mentioned ciphertext report; then, control the above-mentioned authoritative institution to calculate the aggregated ciphertext according to all the above-mentioned ciphertext reports, generate the aggregated report and submit the above-mentioned aggregated report to the above-mentioned initiating bank; finally, the above-mentioned initiating bank decrypts according to the above-mentioned aggregated report to obtain the decrypted asset data, and compares and judges the above-mentioned decrypted asset data with the current overdue asset data of the above-mentioned target customer to obtain the judgment result, so as to verify the total asset situation of the above-mentioned target customer according to the above-mentioned judgment result and execute the corresponding asset collection plan, the above-mentioned current overdue asset data is the overdue and unpaid asset situation of the above-mentioned target customer in the above-mentioned initiating bank. This application is divided into five stages: the registration center key generation stage: the registration center generates a symmetric homomorphic key and sends it securely to the initiating bank and the responding bank; the initiating bank application and authority initialization stage: the initiating bank applies to the authority to view the cross-bank asset situation of a certain customer, and the authority randomly selects the chaotic factor and sends it to the corresponding responding bank in secret; the responding bank ciphertext generation stage: the responding bank calculates the ciphertext based on the customer's asset data in its own bank and sends the ciphertext report to the authority; the authority ciphertext aggregation stage: after receiving the ciphertext report from each responding bank, the authority calculates the aggregated ciphertext and submits it to the initiating bank; the initiating bank ciphertext decryption stage: after receiving the aggregated report from the authority, the initiating bank decrypts the aggregated report and compares the customer's asset data in its own bank with the decrypted data to verify the customer's asset situation. Prepare for the next deduction action. This move fills the possible cross-bank deduction loopholes, improves the collection mechanism, and provides data support for possible legal proceedings, providing a new solution for cross-bank collection.This application solves the problem in the prior art that mutual trust between multiple banks is difficult to achieve and there is a risk of cross-bank privacy leakage of customer data, so that banks cannot know all the asset situations of target customers, resulting in the inability to effectively collect assets across banks. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A hardware structure block diagram of a mobile terminal for executing an inter-bank collection asset verification method provided in an embodiment of the present application is shown;

[0017] Figure 2 A schematic diagram of a process of verifying an inter-bank collection asset provided according to an embodiment of the present application is shown;

[0018] Figure 3 A schematic diagram of the structure of an inter-bank collection asset verification system provided according to an embodiment of the present application is shown;

[0019] Figure 4 An overall flow chart of an inter-bank collection asset verification method provided according to an embodiment of the present application is shown;

[0020] Figure 5 A structural block diagram of an inter-bank collection asset verification device provided according to an embodiment of the present application is shown.

[0021] The above drawings include the following reference numerals:

[0022] 102, processor; 104, memory; 106, transmission device; 108, input and output devices. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] As introduced in the background technology, there are currently almost no feasible inter-bank deduction methods in the prior art. According to the existing deduction ideas, multiple banks need to authorize each other. This approach still has the following disadvantages: (1) The procedures are complicated and redundant, and it is difficult to achieve mutual trust between multiple banks and does not meet compliance requirements; (2) There is a risk of cross-bank privacy leakage of customer data, and personal data is not easy to control in a refined manner. In order to solve the problem in the prior art that it is difficult to achieve mutual trust between multiple banks and there is a risk of cross-bank privacy leakage of customer data, so that banks cannot know all the asset situations of the target customers and cannot conduct effective cross-bank asset collection, the embodiments of the present application provide an inter-bank asset collection verification method, an inter-bank asset collection verification device, a computer-readable storage medium and an inter-bank asset collection verification system.

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0028] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 1 is a hardware structure block diagram of a mobile terminal of an inter-bank collection asset verification method according to an embodiment of the present invention. Figure 1 As shown, the mobile terminal may include one or more ( Figure 1 Only one is shown in the figure) a processor 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data, wherein the mobile terminal may also include a transmission device 106 and an input / output device 108 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the mobile terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0029] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the inter-bank collection asset verification method in the embodiment of the present invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, to implement the above method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the above network include but are not limited to the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. The specific examples of the above network may include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0030] In this embodiment, a method for verifying assets for inter-bank collection that runs on a mobile terminal, a computer terminal, or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in an order different from that shown here.

[0031] Figure 2 Flowchart of the inter-bank collection asset verification method according to an embodiment of the present application. Figure 2 As shown, the method comprises the following steps:

[0032] Step S201, control the registration center to generate a symmetric homomorphic key, and send the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is the bank that signs and participates in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data.

[0033] Specifically, Figure 3 A schematic diagram of the structure of an inter-bank collection asset verification system provided according to an embodiment of the present application is shown; Figure 4 FIG. 1 shows an overall flow chart of an inter-bank collection asset verification method provided according to an embodiment of the present application; Figure 3 As shown in Figure 1, the inter-bank collection asset verification system is abstracted into four entities, namely, the registry center (RC), the initiator bank (IB), the responder bank (RB), and the authority organization (AO). The i-th responding bank is denoted as RB. i .like Figure 4 As shown, the present invention is divided into five stages. The first stage is the registration center key generation stage. In the registration center key generation stage, the registration center generates a symmetric homomorphic key and securely sends it to the initiating bank IB and the responding bank RB. i (i=1, 2, 3…, n).

[0034] It should also be noted that there are other homomorphic encryption technologies that can replace the symmetric homomorphic encryption algorithm in the present invention. However, the present invention achieves better results in terms of overdue customer data privacy protection, resistance to differential attacks, computational costs and communication costs.

[0035] Step S202, the initiating bank sends the inter-bank asset verification request to an authority, so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target responding bank, where the target responding bank is the responding bank that has the target customer.

[0036] Specifically, Figure 4 As shown in the figure, the second stage is the initiating bank application and the initialization stage of the authority. The initiating bank application and the initialization stage of the authority: the initiating bank IB applies to the authority AO to view the cross-bank assets of a certain customer. The authority AO randomly selects the chaotic factors and secretly sends them to the corresponding responding bank RB. i .

[0037] Step S203, control the above-mentioned target response bank to calculate the ciphertext based on the bank asset data of the above-mentioned target customer according to the above-mentioned symmetric homomorphic key, generate a corresponding ciphertext report and send the above-mentioned ciphertext report to the above-mentioned authoritative agency, the above-mentioned bank asset data is the asset data of the above-mentioned target customer in the corresponding above-mentioned target response bank, and one above-mentioned target response bank generates one above-mentioned ciphertext report.

[0038] Specifically, Figure 4 As shown, the third stage is the response bank ciphertext generation stage, which is the response bank RBi (i=1, 2, 3…, n) calculate the ciphertext based on the target customer's asset data in their own bank, generate a ciphertext report based on the ciphertext, and send the ciphertext report to the authoritative organization AO. If a responding bank does not have the target customer, it will not participate in the collection asset verification initiated by the initiating bank. Only the responding bank that has the target customer will participate.

[0039] Step S204, controlling the above-mentioned authoritative institution to calculate the aggregated ciphertext according to all the above-mentioned ciphertext reports, generate an aggregated report and submit the above-mentioned aggregated report to the above-mentioned initiating bank.

[0040] Specifically, Figure 4 As shown, the fourth stage is the authority ciphertext aggregation stage. In the authority ciphertext aggregation stage: multiple target response banks RB are received i After receiving the ciphertext report, the authority AO calculates the aggregated ciphertext based on all the ciphertext reports, generates an aggregated report based on the aggregated ciphertext, and submits the aggregated report to the initiating bank IB.

[0041] Step S205, the initiating bank decrypts the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer based on the judgment result and execute the corresponding asset collection plan. The current overdue asset data is the overdue asset situation of the target customer at the initiating bank.

[0042] Specifically, Figure 4 As shown, the fifth stage is the ciphertext decryption stage of the initiating bank. The ciphertext decryption stage of the initiating bank: after receiving the aggregation report from the authoritative institution AO, the initiating bank IB decrypts the aggregation report, and compares the asset data of the target customer in its own bank (i.e. the above-mentioned current overdue asset data) with the decrypted data (i.e. the above-mentioned decrypted asset data) to verify the asset situation of the target customer. It should be noted that the above-mentioned decrypted asset data represents the sum of the asset data of the above-mentioned target customer in all the above-mentioned target response banks. In order to ensure customer privacy, the initiating bank cannot obtain the asset data of the above-mentioned target customer in each target response bank, and can only obtain the sum of the assets of the target customer in all target response banks.

[0043] In this embodiment, first, the registration center is controlled to generate a symmetric homomorphic key and send the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is a bank that has signed and participated in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data; then, the initiating bank sends the inter-bank asset verification request to the authority, so that the authority randomly selects the chaotic factor and sends the chaotic factor to the initiating bank and the target response bank. The target response bank is the response bank that owns the target customer; then, the target response bank is controlled to generate a symmetric homomorphic key. The bank calculates the ciphertext based on the bank asset data of the target customer according to the symmetric homomorphic key, generates a corresponding ciphertext report and sends the ciphertext report to the authoritative institution. The bank asset data is the asset data of the target customer in the corresponding target response bank, and one target response bank generates one ciphertext report. Afterwards, the authoritative institution is controlled to calculate the aggregated ciphertext according to all the ciphertext reports, generate an aggregated report and submit the aggregated report to the initiating bank. Finally, the initiating bank decrypts the aggregated report to obtain the decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer according to the judgment result and execute the corresponding asset collection plan. The current overdue asset data is the overdue asset situation of the target customer in the initiating bank. This application is divided into five stages: the registration center key generation stage: the registration center generates a symmetric homomorphic key and sends it securely to the initiating bank and the responding bank; the initiating bank application and authority initialization stage: the initiating bank applies to the authority to view the cross-bank asset situation of a certain customer, and the authority randomly selects the chaotic factor and sends it to the corresponding responding bank in secret; the responding bank ciphertext generation stage: the responding bank calculates the ciphertext based on the customer's asset data in its own bank and sends the ciphertext report to the authority; the authority ciphertext aggregation stage: after receiving the ciphertext report from each responding bank, the authority calculates the aggregated ciphertext and submits it to the initiating bank; the initiating bank ciphertext decryption stage: after receiving the aggregated report from the authority, the initiating bank decrypts the aggregated report and compares the customer's asset data in its own bank with the decrypted data to verify the customer's asset situation. Prepare for the next deduction action. This move fills the possible cross-bank deduction loopholes, improves the collection mechanism, and provides data support for possible legal proceedings, providing a new solution for cross-bank collection.This application solves the problem in the prior art that mutual trust between multiple banks is difficult to achieve and there is a risk of cross-bank privacy leakage of customer data, so that banks cannot know all the asset situations of target customers, resulting in the inability to effectively collect assets across banks.

[0044] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the implementation process of the inter-bank collection asset verification method of the present application will be described in detail below in conjunction with specific embodiments.

[0045] In order to ensure the security and reliability of the subsequently generated ciphertext, in an optional implementation manner, the above step S201 includes:

[0046] Step S2011, controlling the registration center to select a first prime number, a second prime number, a first random parameter, and a ciphertext level, and calculating a public parameter according to the product of the first prime number and the second prime number, wherein the first prime number is greater than the second prime number;

[0047] Step S2012, generating the symmetric homomorphic key according to the second prime number, the first random parameter and the ciphertext level.

[0048] In the above embodiment, the registration center RC selects two large prime numbers p (i.e., the first prime number) and q (i.e., the second prime number) to satisfy p>>q. Randomly select s (i.e. the first random parameter mentioned above), select a small positive integer d, d represents the ciphertext level, and calculate the public parameter N = pq. The registration center RC securely sends the symmetric homomorphic key <s, d, q> to all banks that comply with the protocol, including the initiating bank IB and the responding bank RB. i (i=1, 2, ..., n), where stands for the p-order multiplication group, which is the set of all integers from 1 to p-1 that are not divisible by p. These integers form a cyclic group under multiplication modulo p.

[0049] In order to resist differential attacks, in an optional implementation manner, the above step S202 includes:

[0050] Step S2021, the initiating bank sends the inter-bank asset verification request to the authoritative institution to apply for checking the inter-bank asset status of the target customer, so that the authoritative institution queries the corresponding responding bank according to the inter-bank asset verification request to obtain the target responding bank;

[0051] Step S2022, controlling the above authority to randomly select the above chaos factor k i , and send the above chaotic factors to the corresponding above response banks, the above chaotic factors satisfy k1+k2+…+k i +…+kn =0modN.

[0052] In the above embodiment, the initiating bank IB applies to the authority AO to view the cross-bank assets of a certain customer (i.e. the above target customer). After the approval process is completed, the authority AO randomly selects the chaotic factor Satisfies k1+k2+…+k i +…+k n = 0 mod N. The authority AO defines the chaos factor k i Secretly sent to the corresponding response bank RB i . Realize the privacy protection of overdue customer data and resist differential attacks. The use of aggregation algorithm will not disclose the detailed asset situation of individual overdue customers in a certain bank, and the total assets of the customer can still be verified. Suppose the initiating bank IB obtains the ciphertext C=C1+C2+C3mod N at one time, and obtains the ciphertext C=C1+C2mod N without changing the plaintext. According to the conventional idea, after decryption respectively, the plaintext m3 can be obtained by subtracting the two values. However, the present invention has the existence of chaotic factors k1 and k2, and the value obtained by decrypting the ciphertext C=C1+C2mod N will be confused, which can resist differential attacks. Prevent tampering: The chaotic factor can be used as a verification mechanism to ensure that the information has not been tampered with during transmission. Privacy protection: By using chaotic factors, the customer's sensitive information will not be directly exposed, thereby protecting the customer's privacy.

[0053] In order to share necessary information with the responding bank without leaking customer privacy, in an optional implementation, the above step S203 includes:

[0054] Step S2031, controlling the target response bank to obtain plain text according to the bank asset data of the target customer in its own bank, and selecting a second random parameter, the sum of the absolute value of the second random parameter and the absolute value of the second prime number being less than the absolute value of the public parameter;

[0055] Step S2032, control the target response bank to use the symmetric homomorphic key and the plaintext to calculate the ciphertext according to the first formula, where the first formula is C i =s d (r i q+m i +k i )mod N,C i represents the ciphertext of the i-th target response bank, s represents the first random parameter, d represents the ciphertext level, r i represents the second random parameter selected by the i-th target response bank, m i represents the plaintext obtained by the i-th target response bank, ki represents the chaos factor sent to the i-th target response bank, and N represents the public parameter;

[0056] Step S2033, controlling the target response bank to generate the ciphertext report according to the ciphertext, and sending the ciphertext report to the authority, wherein the ciphertext report includes the current timestamp, the ciphertext and the identity of the target response bank.

[0057] In the above embodiment, the responding bank RB i (i=1, 2, ..., n) respectively obtain the plaintext m based on the customer asset data in their own bank i , choose a random number r i (i.e. the second random parameter mentioned above) satisfies |r i |+|q|<|N|, using symmetric homomorphic keys<s,d,q> , calculate the ciphertext C i =s u (r i q+m i +k i )mod N. Response Bank RB i All send encrypted reports to the authority AO <C i , ID i , T>, where T represents the current timestamp, ID i Indicates the responding bank RB i Identity. The generation and sending of encrypted reports is to provide necessary information to the authorities while ensuring the security and privacy of the information. The inclusion of a timestamp can ensure the timeliness of the report and prevent the information from being tampered with. The inclusion of user identity identification helps the authorities track and verify the source of the information. In this way, banks can share necessary information with the target responding banks to meet compliance requirements without disclosing customer privacy. It should also be noted that the use of the encryption algorithm of the present invention can consume less computing time. The Paillier encryption algorithm and the method of the present invention are used to perform encryption calculations on n responding banks respectively, and the computing efficiency of the two is compared. Paillier's encryption algorithm is The encryption algorithm in this paper is C i =s d (r i q+m i )mod N, the encryption algorithm comparison is shown in Table 1:

[0058] Table 1

[0059] algorithm Addition Multiplication Exponential Operation Paillier algorithm 0 n 2n The present invention n 2n n

[0060] Compared with the Paillier method, the present invention uses more n addition operations and n multiplication operations, and uses fewer n exponential operations. The computational time of exponential operations is significantly higher than that of addition operations and multiplication operations. 2 The present invention is calculated under modulo N, and the addition, multiplication and operation of the present invention are less time-consuming than the Paillier algorithm. Therefore, the present invention consumes less calculation time.

[0061] The encryption algorithm of the present invention can also occupy less communication bandwidth. Assume that the length of N is x bits.

[0062] Table 2

[0063] algorithm Ciphertext length Paillier algorithm 2x The present invention x

[0064] As shown in Table 2 above, the present invention is calculated under modulus N, the length of the ciphertext is x bits, and the Paillier algorithm is calculated under modulus N. 2 Calculated below, the ciphertext length is 2x bits. Obviously, when transmitting ciphertext, the present invention saves half of the communication bandwidth.

[0065] In order to improve the security and efficiency of data processing, in an optional implementation, the above step S204 includes:

[0066] Step S2041, control the above-mentioned authority to receive all the above-mentioned ciphertext reports and calculate the above-mentioned aggregated ciphertext according to the second formula, the above-mentioned second formula is C=C1+C2+…+C i +…+C n mod N,C i represents the ciphertext of the i-th target response bank, and C represents the above aggregated ciphertext;

[0067] Step S2042, controlling the above-mentioned authoritative institution to generate the above-mentioned aggregate report according to the above-mentioned aggregate ciphertext, and sending the above-mentioned aggregate report to the above-mentioned initiating bank, wherein the above-mentioned ciphertext report includes the current timestamp, the above-mentioned aggregate ciphertext and the identity of the above-mentioned authoritative institution.

[0068] In the above embodiment, the authority first needs to establish a secure communication channel to ensure the security and integrity of the encrypted reports sent by all target response banks during the transmission process. <C i , ID i , T>, the authority AO calculates the aggregate ciphertext C = C1 + C2 + ... + C i +…+C n mod N. The authority AO sends an aggregate report to the initiating bank IB <C,ID AO , T>, where T represents the current timestamp, ID AOThe identity of the authority AO is represented to ensure the traceability and authority of the report. Encryption ensures that the privacy of data is not leaked during transmission and processing. Even if the data is encrypted, the authority can still aggregate the ciphertext through the characteristics of additive homomorphic encryption to obtain an overall data view without accessing the original data. The authority sends the aggregated report to the initiating bank through a secure communication channel. In this process, the security and integrity of data transmission also need to be ensured. The aggregated report contains the identity of the authority, which increases the credibility of the report and allows the initiating bank to verify the source of the report. The inclusion of the current timestamp ensures the timeliness of the report, allowing effective aggregation and analysis of encrypted data while protecting data privacy, thereby improving the security and efficiency of data processing.

[0069] In order to determine whether the target customer's assets are sufficient to cover its overdue debts, in an optional implementation, the above step S205 includes:

[0070] Step S2051, after receiving the above-mentioned aggregate report sent by the above-mentioned authoritative institution, the initiating bank uses the above-mentioned homomorphic encryption key to perform decryption using a symmetric homomorphic encryption algorithm according to the above-mentioned aggregate report to obtain the above-mentioned decrypted asset data;

[0071] Step S2052, comparing the decrypted asset data with the current overdue asset data;

[0072] Step S2053, when the decrypted asset data is greater than or equal to the current overdue asset data, it is determined that the target customer has the fully repayable assets;

[0073] Step S2054: when the decrypted asset data is less than the current overdue asset data and the decrypted asset data is greater than zero, it is determined that the target customer has partially repayable assets;

[0074] Step S2055: when the decrypted asset data is less than or equal to zero, it is determined that the target customer has no assets.

[0075] In the above embodiment, the above judgment result is that the above target customer has fully repayable assets, or the above target customer has partially repayable assets, or the above target customer has no assets. The above fully repayable assets mean that the sum of the above target customer's assets in all the above target response banks can repay all the debts owed to the above initiating bank, and the above partially repayable assets mean that the sum of the above target customer's assets in all the above target response banks cannot fully repay all the debts owed to the above initiating bank. The initiating bank IB receives the aggregation report from the authority AO <C, ID AO, T>, decrypt and calculate ∑m i =(C×s -d mod N) mod q. The initiating bank IB compares the customer's asset data in its own bank with the total asset data of the customer in other banks obtained by decryption. Based on the judgment result, the initiating bank IB can further perform inter-bank deduction and other tasks. The correctness of decryption is shown in the following formula: The initiating bank compares the decrypted asset data with the current overdue asset data of the target customer to determine whether the target customer's assets are sufficient to cover its overdue debts. Through the comparison, the bank can evaluate the target customer's ability to repay debts and make corresponding credit decisions. If the decrypted asset data is greater than or equal to the current overdue asset data, the initiating bank determines that the target customer has fully repayable assets. This means that the sum of the target customer's assets in all target response banks is sufficient to cover all of its overdue debts. If the decrypted asset data is less than the current overdue asset data, but greater than zero, the initiating bank determines that the target customer has repayable assets. This means that the sum of the target customer's assets in all target response banks is not enough to cover all overdue debts, but can repay part of the debt. If the decrypted asset data is less than or equal to zero, the initiating bank determines that the target customer has no assets. This means that the target customer does not have enough assets to repay any overdue debts. Banks can take stricter risk control measures based on this, such as rejecting new loan applications or taking legal action. Banks may take more active debt recovery measures, such as recovering debts through legal means. While protecting customer privacy, it helps banks evaluate customers' credit status and repayment ability, so as to make more reasonable decisions.

[0076] In order to ensure the legitimacy of the debt collection behavior, in an optional implementation manner, after the above step S205, the method further includes:

[0077] Step S301, when the above judgment result is that the above target customer has the above fully repayable assets or the above judgment result is that the above target customer has the above partially repayable assets, determine the above asset collection plan as inter-bank deductions executed by court litigation.

[0078] In the above embodiment, after confirming the existence of the assets, a review is required to ensure that the collection behavior complies with laws and regulations. File a lawsuit with the court and request the court to rule to allow the execution of inter-bank deductions. Once the court ruling is supported, the inter-bank deduction operation is executed to deduct the target customer's assets from the target response bank to the target customer's account in the initiating bank. The execution of inter-bank deductions through court litigation can ensure the legality of the collection behavior. It should be noted that the collection of assets needs to strictly comply with relevant laws and regulations to ensure that all actions are carried out within the scope permitted by law. At the same time, it is also necessary to take into account the actual situation of the debtor to avoid unnecessary problems caused by excessive collection. Of course, there may also be other plans for collecting assets, such as negotiations with target customers.

[0079] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0080] The embodiment of the present application also provides an inter-bank collection asset verification device. It should be noted that the inter-bank collection asset verification device of the embodiment of the present application can be used to execute the inter-bank collection asset verification method provided by the embodiment of the present application. The device is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware for a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived.

[0081] The following is an introduction to the inter-bank collection asset verification device provided in an embodiment of the present application.

[0082] Figure 5 is a structural block diagram of the inter-bank collection asset verification device according to an embodiment of the present application. Figure 5 As shown, the device comprises:

[0083] The first control unit 10 is used to control the registration center to generate a symmetric homomorphic key and send the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is the bank that signs and participates in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement for sharing asset data to verify customer assets under the premise of ensuring the privacy of bank customer data.

[0084] Specifically, Figure 3A schematic diagram of the structure of an inter-bank collection asset verification system provided according to an embodiment of the present application is shown; Figure 4 FIG. 1 shows an overall flow chart of an inter-bank collection asset verification method provided according to an embodiment of the present application; Figure 3 As shown in Figure 1, the inter-bank collection asset verification system is abstracted into four entities, namely, the registry center (RC), the initiator bank (IB), the responder bank (RB), and the authority organization (AO). The i-th responding bank is denoted as RB. i .like Figure 4 As shown, the present invention is divided into five stages. The first stage is the registration center key generation stage. In the registration center key generation stage, the registration center generates a symmetric homomorphic key and securely sends it to the initiating bank IB and the responding bank RB. i (i=1, 2, 3…, m).

[0085] It should also be noted that there are other homomorphic encryption technologies that can replace the symmetric homomorphic encryption algorithm in the present invention. However, the present invention achieves better results in terms of overdue customer data privacy protection, resistance to differential attacks, computational costs and communication costs.

[0086] The initiating unit 20 is used for the initiating bank to send the inter-bank asset verification request to the authority, so that the authority randomly selects the chaotic factor and sends the chaotic factor to the initiating bank and the target response bank, and the target response bank is the response bank that has the target customer.

[0087] Specifically, Figure 4 As shown in the figure, the second stage is the initiating bank application and the initialization stage of the authority. The initiating bank application and the initialization stage of the authority: the initiating bank IB applies to the authority AO to view the cross-bank assets of a certain customer. The authority AO randomly selects the chaotic factors and secretly sends them to the corresponding responding bank RB. i .

[0088] The second control unit 30 is used to control the above-mentioned target response bank to calculate the ciphertext based on the bank asset data of the above-mentioned target customer according to the above-mentioned symmetric homomorphic key, generate a corresponding ciphertext report and send the above-mentioned ciphertext report to the above-mentioned authoritative agency. The above-mentioned bank asset data is the asset data of the above-mentioned target customer in the corresponding above-mentioned target response bank, and one above-mentioned target response bank generates one above-mentioned ciphertext report.

[0089] Specifically, Figure 4 As shown, the third stage is the response bank ciphertext generation stage, which is the response bank RBi (i=1, 2, 3…, n) calculate the ciphertext based on the target customer's asset data in their own bank, generate a ciphertext report based on the ciphertext, and send the ciphertext report to the authoritative organization AO. If a responding bank does not have the target customer, it will not participate in the collection asset verification initiated by the initiating bank. Only the responding bank that has the target customer will participate.

[0090] The third control unit 40 is used to control the above-mentioned authoritative institution to calculate the aggregated ciphertext according to all the above-mentioned ciphertext reports, generate the aggregated report and submit the above-mentioned aggregated report to the above-mentioned initiating bank.

[0091] Specifically, Figure 4 As shown, the fourth stage is the authority ciphertext aggregation stage. In the authority ciphertext aggregation stage: multiple target response banks RB are received i After receiving the ciphertext report, the authority AO calculates the aggregated ciphertext based on all the ciphertext reports, generates an aggregated report based on the aggregated ciphertext, and submits the aggregated report to the initiating bank IB.

[0092] The decryption unit 50 is used for the initiating bank to decrypt according to the above-mentioned aggregate report to obtain decrypted asset data, and compare and judge the above-mentioned decrypted asset data with the current overdue asset data of the above-mentioned target customer to obtain a judgment result, so as to verify the total asset situation of the above-mentioned target customer according to the above-mentioned judgment result and execute the corresponding asset collection plan. The above-mentioned current overdue asset data is the overdue and unpaid asset situation of the above-mentioned target customer at the initiating bank.

[0093] Specifically, Figure 4 As shown, the fifth stage is the ciphertext decryption stage of the initiating bank. The ciphertext decryption stage of the initiating bank: after receiving the aggregation report from the authoritative institution AO, the initiating bank IB decrypts the aggregation report, and compares the asset data of the target customer in its own bank (i.e. the above-mentioned current overdue asset data) with the decrypted data (i.e. the above-mentioned decrypted asset data) to verify the asset situation of the target customer. It should be noted that the above-mentioned decrypted asset data represents the sum of the asset data of the above-mentioned target customer in all the above-mentioned target response banks. In order to ensure customer privacy, the initiating bank cannot obtain the asset data of the above-mentioned target customer in each target response bank, and can only obtain the sum of the assets of the target customer in all target response banks.

[0094] In this embodiment, the first control unit is used to control the registration center to generate a symmetric homomorphic key and send the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is a bank that has signed and participated in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data; the initiating unit is used for the initiating bank to send the inter-bank asset verification request to the authority so that the authority randomly selects the chaotic factor and sends the chaotic factor to the initiating bank and the target response bank. The target response bank is the response bank that owns the target customer; the second control unit is used to control the target The target response bank calculates the ciphertext based on the bank asset data of the target customer according to the above-mentioned symmetric homomorphic key, generates a corresponding ciphertext report and sends the above-mentioned ciphertext report to the above-mentioned authoritative institution, the above-mentioned bank asset data is the asset data of the above-mentioned target customer in the corresponding above-mentioned target response bank, and one above-mentioned target response bank generates one above-mentioned ciphertext report; the third control unit is used to control the above-mentioned authoritative institution to calculate the aggregated ciphertext according to all the above-mentioned ciphertext reports, generate an aggregated report and submit the above-mentioned aggregated report to the above-mentioned initiating bank; the decryption unit is used for the above-mentioned initiating bank to decrypt according to the above-mentioned aggregated report to obtain the decrypted asset data, and compare and judge the above-mentioned decrypted asset data with the current overdue asset data of the above-mentioned target customer to obtain a judgment result, so as to verify the total asset situation of the above-mentioned target customer according to the above-mentioned judgment result and execute the corresponding asset collection plan, the above-mentioned current overdue asset data is the overdue and unpaid asset situation of the above-mentioned target customer in the above-mentioned initiating bank. This application is divided into five stages: the registration center key generation stage: the registration center generates a symmetric homomorphic key and sends it securely to the initiating bank and the responding bank; the initiating bank application and authority initialization stage: the initiating bank applies to the authority to view the cross-bank asset situation of a certain customer, and the authority randomly selects the chaotic factor and sends it to the corresponding responding bank in secret; the responding bank ciphertext generation stage: the responding bank calculates the ciphertext based on the customer's asset data in its own bank and sends the ciphertext report to the authority; the authority ciphertext aggregation stage: after receiving the ciphertext report from each responding bank, the authority calculates the aggregated ciphertext and submits it to the initiating bank; the initiating bank ciphertext decryption stage: after receiving the aggregated report from the authority, the initiating bank decrypts the aggregated report and compares the customer's asset data in its own bank with the decrypted data to verify the customer's asset situation. Prepare for the next deduction action. This move fills the possible cross-bank deduction loopholes, improves the collection mechanism, and provides data support for possible legal proceedings, providing a new solution for cross-bank collection.This application solves the problem in the prior art that mutual trust between multiple banks is difficult to achieve and there is a risk of cross-bank privacy leakage of customer data, so that banks cannot know all the asset situations of target customers, resulting in the inability to effectively collect assets across banks.

[0095] In order to ensure the security and reliability of the subsequently generated ciphertext, in an optional implementation manner, the first control unit includes:

[0096] A first control module is used to control the registration center to select a first prime number, a second prime number, a first random parameter, and a ciphertext level, and calculate a public parameter according to the product of the first prime number and the second prime number, wherein the first prime number is greater than the second prime number;

[0097] A generation module is used to generate the above-mentioned symmetric homomorphic key according to the above-mentioned second prime number, the above-mentioned first random parameter and the above-mentioned ciphertext level.

[0098] In the above embodiment, the registration center RC selects two large prime numbers p (i.e., the first prime number) and q (i.e., the second prime number) to satisfy p>>q. Randomly select s (i.e. the first random parameter mentioned above), select a small positive integer d, d represents the ciphertext level, and calculate the public parameter N = pq. The registration center RC securely sends the symmetric homomorphic key <s, d, q> to all banks that comply with the protocol, including the initiating bank IB and the responding bank RB. i (i=1, 2, ..., n), where stands for the p-order multiplication group, which is the set of all integers from 1 to p-1 that are not divisible by p. These integers form a cyclic group under multiplication modulo p.

[0099] In order to resist differential attacks, in an optional implementation manner, the initiating unit includes:

[0100] A request sending module, configured for the initiating bank to send the inter-bank asset verification request to the authoritative institution to apply for checking the inter-bank asset status of the target customer, so that the authoritative institution can query the corresponding responding bank according to the inter-bank asset verification request to obtain the target responding bank;

[0101] The second control module is used to control the above-mentioned authority to randomly select the above-mentioned chaotic factor k i , and send the above chaotic factors to the corresponding above response banks, the above chaotic factors satisfy k1+k2+…+k i +…+k n =0 mod N.

[0102] In the above embodiment, the initiating bank IB applies to the authority AO to view the cross-bank assets of a certain customer (i.e., the above target customer). After the approval process is completed, the authority AO randomly selects the chaotic factor k. i (i=1,2,…,n), satisfying k1+k2+…+k i +…+k n = 0 mod N. The authority AO defines the chaos factor k i Secretly sent to the corresponding response bank RB i . Realize the privacy protection of overdue customer data and resist differential attacks. The use of aggregation algorithm will not disclose the detailed asset situation of individual overdue customers in a certain bank, and the total assets of the customer can still be verified. Suppose the initiating bank IB obtains the ciphertext C=C1+C2+C3mod N at one time, and obtains the ciphertext C=C1+C2mod N without changing the plaintext. According to the conventional idea, after decryption respectively, the plaintext m3 can be obtained by subtracting the two values. However, the present invention has the existence of chaotic factors k1 and k2, and the value obtained by decrypting the ciphertext C=C1+C2mod N will be confused, which can resist differential attacks. Prevent tampering: The chaotic factor can be used as a verification mechanism to ensure that the information has not been tampered with during transmission. Privacy protection: By using chaotic factors, the customer's sensitive information will not be directly exposed, thereby protecting the customer's privacy.

[0103] In order to share necessary information with the responding bank without leaking customer privacy, in an optional implementation, the second control unit includes:

[0104] A third control module controls the target response bank to obtain the plain text according to the bank asset data of the target customer in its own bank, and select a second random parameter, wherein the sum of the absolute value of the second random parameter and the absolute value of the second prime number is less than the absolute value of the public parameter;

[0105] The fourth control module is used to control the target response bank to calculate the ciphertext using the symmetric homomorphic key and the plaintext according to the first formula, where the first formula is C i =s d (r i q+m i +k i )mod N,C i represents the ciphertext of the i-th target response bank, s represents the first random parameter, d represents the ciphertext level, r i represents the second random parameter selected by the i-th target response bank, m i represents the plaintext obtained by the i-th target response bank, k irepresents the chaos factor sent to the i-th target response bank, and N represents the public parameter;

[0106] The fifth control module is used to control the target response bank to generate the ciphertext report according to the ciphertext, and send the ciphertext report to the authority, wherein the ciphertext report includes the current timestamp, the ciphertext and the identity of the target response bank.

[0107] In the above embodiment, the responding bank RB i (i=1, 2, ..., n) respectively obtain the plaintext m based on the customer asset data in their own bank i , choose a random number r i (i.e. the second random parameter mentioned above) satisfies |r i |+|q|<|N|, using symmetric homomorphic keys<s,d,q> , calculate the ciphertext C i =s d (r i q+m i +k i )mod N. Response Bank RB i All send encrypted reports to the authority AO<C i , ID i , T>, where T represents the current timestamp, ID i Indicates the responding bank RB i Identity. The generation and sending of encrypted reports is to provide the necessary information to the authorities while ensuring the security and privacy of the information. Including a timestamp ensures the timeliness of the report and prevents information from being tampered with. Including user identification helps authorities track and verify the source of the information. In this way, banks can share the necessary information with the target responding banks to meet compliance requirements without compromising customer privacy.

[0108] It should also be noted that the encryption algorithm of the present invention can consume less computing time. The Paillier encryption algorithm and the method of the present invention are respectively used to perform encryption calculations on n responding banks, and the computing efficiencies of the two are compared.

[0109] Paillier's encryption algorithm is The encryption algorithm in this paper is C i =s d (r i q+m i )mod N, the encryption algorithm comparison is shown in Table 1:

[0110] Table 1

[0111] algorithm Addition Multiplication Exponential Operation Paillier algorithm 0 nn 2nn The present invention n 2n n

[0112] Compared with the Paillier method, the present invention uses more n addition operations and n multiplication operations, and uses fewer n exponential operations. The computational time of exponential operations is significantly higher than that of addition operations and multiplication operations. 2 The present invention is calculated under modulo N, and the addition, multiplication and operation of the present invention are less time-consuming than the Paillier algorithm. Therefore, the present invention consumes less calculation time.

[0113] The encryption algorithm of the present invention can also occupy less communication bandwidth. Assume that the length of N is x bits.

[0114] Table 2

[0115] algorithm Ciphertext length Paillier algorithm 2x The present invention x

[0116] As shown in Table 2 above, the present invention is calculated under modulus N, the length of the ciphertext is x bits, and the Paillier algorithm is calculated under modulus N. 2 Calculated below, the ciphertext length is 2x bits. Obviously, when transmitting ciphertext, the present invention saves half of the communication bandwidth.

[0117] In order to improve the security and efficiency of data processing, in an optional implementation manner, the third control unit includes:

[0118] The sixth control module is used to control the above-mentioned authority to receive all the above-mentioned ciphertext reports and calculate the above-mentioned aggregated ciphertext according to the second formula, where the above-mentioned second formula is C=C1+C2+…+C i +…+C n mod N,C i represents the ciphertext of the i-th target response bank, and C represents the above aggregated ciphertext;

[0119] The seventh control module is used to control the above-mentioned authoritative institution to generate the above-mentioned aggregate report according to the above-mentioned aggregate ciphertext, and send the above-mentioned aggregate report to the above-mentioned initiating bank. The above-mentioned ciphertext report includes a current timestamp, the above-mentioned aggregate ciphertext and the identity identifier of the above-mentioned authoritative institution.

[0120] In the above embodiment, the authority first needs to establish a secure communication channel to ensure the security and integrity of the encrypted reports sent by all target response banks during the transmission process. <C i , ID i , T>, the authority AO calculates the aggregate ciphertext C = C1 + C2 + ... + C i +…+C n mod N. The authority AO sends an aggregate report to the initiating bank IB <C, ID AO , T>, where T represents the current timestamp, ID AOThe identity of the authority AO is represented to ensure the traceability and authority of the report. Encryption ensures that the privacy of data is not leaked during transmission and processing. Even if the data is encrypted, the authority can still aggregate the ciphertext through the characteristics of additive homomorphic encryption to obtain an overall data view without accessing the original data. The authority sends the aggregated report to the initiating bank through a secure communication channel. In this process, the security and integrity of data transmission also need to be ensured. The aggregated report contains the identity of the authority, which increases the credibility of the report and allows the initiating bank to verify the source of the report. The inclusion of the current timestamp ensures the timeliness of the report, allowing effective aggregation and analysis of encrypted data while protecting data privacy, thereby improving the security and efficiency of data processing.

[0121] In order to determine whether the target customer's assets are sufficient to cover its overdue debts, in an optional implementation, the decryption unit includes:

[0122] A decryption module is used for the initiating bank to decrypt the aggregate report sent by the authoritative institution using the homomorphic encryption key and the symmetric homomorphic encryption algorithm according to the aggregate report to obtain the decrypted asset data;

[0123] A comparison module, used to compare the decrypted asset data with the current overdue asset data;

[0124] A first determination module is used to determine that the target customer has the fully repayable assets when the decrypted asset data is greater than or equal to the current overdue asset data;

[0125] A second determination module is used to determine that the target customer has partially repayable assets when the decrypted asset data is less than the current overdue asset data and the decrypted asset data is greater than zero;

[0126] The third determination module is used to determine that the determination result is that the target customer has no assets when the decrypted asset data is less than or equal to zero.

[0127] In the above embodiment, the above judgment result is that the above target customer has fully repayable assets, or the above target customer has partially repayable assets, or the above target customer has no assets. The above fully repayable assets mean that the sum of the above target customer's assets in all the above target response banks can repay all the debts owed to the above initiating bank, and the above partially repayable assets mean that the sum of the above target customer's assets in all the above target response banks cannot fully repay all the debts owed to the above initiating bank. The initiating bank IB receives the aggregation report from the authority AO <C, ID AO, T>, decrypt and calculate ∑m i =(C×s -d mod N)modq. The initiating bank IB compares the customer's asset data in its own bank with the total asset data of the customer in other banks obtained by decryption. Based on the judgment result, the initiating bank IB can further perform inter-bank deduction and other tasks. The correctness of decryption is shown in the following formula: The initiating bank compares the decrypted asset data with the current overdue asset data of the target customer to determine whether the target customer's assets are sufficient to cover its overdue debts. Through the comparison, the bank can evaluate the target customer's ability to repay the debt and make corresponding credit decisions. If the decrypted asset data is greater than or equal to the current overdue asset data, the initiating bank determines that the target customer has fully repayable assets. This means that the sum of the target customer's assets in all target response banks is sufficient to cover all of its overdue debts. If the decrypted asset data is less than the current overdue asset data, but greater than zero, the initiating bank determines that the target customer has partially repayable assets. This means that the sum of the target customer's assets in all target response banks is not enough to cover all overdue debts, but part of the debt can be repaid. If the decrypted asset data is less than or equal to zero, the initiating bank determines that the target customer has no assets. This means that the target customer does not have enough assets to repay any overdue debts. Banks can take stricter risk control measures based on this, such as rejecting new loan applications or taking legal action. Banks may take more active debt recovery measures, such as recovering debts through legal means. While protecting customer privacy, it helps banks evaluate customers' credit status and repayment ability, so as to make more reasonable decisions.

[0128] In order to ensure the legitimacy of the debt collection behavior, in an optional implementation manner, the device further includes:

[0129] A determination unit is used to decrypt the aggregate report at the initiating bank to obtain decrypted asset data, and compare the decrypted asset data with the current overdue asset data of the target customer. After obtaining the judgment result, if the judgment result is that the target customer has the fully repayable assets or the judgment result is that the target customer has the partially repayable assets, determine that the asset collection plan is an inter-bank deduction for court litigation execution.

[0130] In the above embodiment, after confirming the existence of the assets, a review is required to ensure that the collection behavior complies with laws and regulations. File a lawsuit with the court and request the court to rule to allow the execution of inter-bank deductions. Once the court ruling is supported, the inter-bank deduction operation is executed to deduct the target customer's assets from the target response bank to the target customer's account in the initiating bank. The execution of inter-bank deductions through court litigation can ensure the legality of the collection behavior. It should be noted that the collection of assets needs to strictly comply with relevant laws and regulations to ensure that all actions are carried out within the scope permitted by law. At the same time, it is also necessary to take into account the actual situation of the debtor to avoid unnecessary problems caused by excessive collection. Of course, there may also be other plans for collecting assets, such as negotiations with target customers.

[0131] The above-mentioned inter-bank collection asset verification device includes a processor and a memory. The above-mentioned first control unit, initiating unit, and second control unit are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to realize corresponding functions. The above-mentioned modules are all located in the same processor; or, the above-mentioned modules are located in different processors in any combination.

[0132] The processor includes a kernel, which retrieves the corresponding program unit from the memory. One or more kernels can be set, and the kernel parameters can be adjusted to solve the problem in the prior art that it is difficult to achieve mutual trust between multiple banks and there is a risk of cross-bank privacy leakage of customer data, so that banks cannot know all the asset conditions of the target customers, resulting in the inability to effectively collect assets across banks.

[0133] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0134] An embodiment of the present invention provides a computer-readable storage medium, which includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute the inter-bank collection asset verification method.

[0135] Specifically, the inter-bank collection asset verification methods include:

[0136] Step S201, control the registration center to generate a symmetric homomorphic key, and send the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is a bank that has signed and participated in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data;

[0137] Step S202, the initiating bank sends the inter-bank asset verification request to an authority, so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target responding bank, where the target responding bank is the responding bank that has the target customer;

[0138] Step S203, controlling the target response bank to calculate the ciphertext according to the symmetric homomorphic key based on the bank asset data of the target customer, generate a corresponding ciphertext report and send the ciphertext report to the authority, wherein the bank asset data is the asset data of the target customer in the corresponding target response bank, and one target response bank generates one ciphertext report;

[0139] Step S204, controlling the above-mentioned authority to calculate the aggregated ciphertext according to all the above-mentioned ciphertext reports, generate an aggregated report and submit the above-mentioned aggregated report to the above-mentioned initiating bank;

[0140] Step S205, the initiating bank decrypts the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer based on the judgment result and execute the corresponding asset collection plan. The current overdue asset data is the overdue asset situation of the target customer at the initiating bank.

[0141] An embodiment of the present invention provides a processor, which is used to run a program, wherein the inter-bank collection asset verification method is executed when the program is running.

[0142] Specifically, the inter-bank collection asset verification methods include:

[0143] Step S201, control the registration center to generate a symmetric homomorphic key, and send the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is a bank that has signed and participated in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data;

[0144] Step S202, the initiating bank sends the inter-bank asset verification request to an authority, so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target responding bank, where the target responding bank is the responding bank that has the target customer;

[0145] Step S203, controlling the target response bank to calculate the ciphertext according to the symmetric homomorphic key based on the bank asset data of the target customer, generate a corresponding ciphertext report and send the ciphertext report to the authority, wherein the bank asset data is the asset data of the target customer in the corresponding target response bank, and one target response bank generates one ciphertext report;

[0146] Step S204, controlling the above-mentioned authority to calculate the aggregated ciphertext according to all the above-mentioned ciphertext reports, generate an aggregated report and submit the above-mentioned aggregated report to the above-mentioned initiating bank;

[0147] Step S205, the initiating bank decrypts the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer based on the judgment result and execute the corresponding asset collection plan. The current overdue asset data is the overdue asset situation of the target customer at the initiating bank.

[0148] An embodiment of the present invention provides an inter-bank collection asset verification system, the inter-bank collection asset verification system comprising a processor, a memory, and a program stored in the memory and executable on the processor, and when the processor executes the program, at least the following steps are implemented:

[0149] Step S201, control the registration center to generate a symmetric homomorphic key, and send the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is a bank that has signed and participated in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data;

[0150] Step S202, the initiating bank sends the inter-bank asset verification request to an authority, so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target responding bank, where the target responding bank is the responding bank that has the target customer;

[0151] Step S203, controlling the target response bank to calculate the ciphertext according to the symmetric homomorphic key based on the bank asset data of the target customer, generate a corresponding ciphertext report and send the ciphertext report to the authority, wherein the bank asset data is the asset data of the target customer in the corresponding target response bank, and one target response bank generates one ciphertext report;

[0152] Step S204, controlling the above-mentioned authority to calculate the aggregated ciphertext according to all the above-mentioned ciphertext reports, generate an aggregated report and submit the above-mentioned aggregated report to the above-mentioned initiating bank;

[0153] Step S205, the initiating bank decrypts the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer based on the judgment result and execute the corresponding asset collection plan. The current overdue asset data is the overdue asset situation of the target customer at the initiating bank.

[0154] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program for initializing at least the following method steps:

[0155] Step S201, control the registration center to generate a symmetric homomorphic key, and send the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is a bank that has signed and participated in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data;

[0156] Step S202, the initiating bank sends the inter-bank asset verification request to an authority, so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target responding bank, where the target responding bank is the responding bank that has the target customer;

[0157] Step S203, controlling the target response bank to calculate the ciphertext according to the symmetric homomorphic key based on the bank asset data of the target customer, generate a corresponding ciphertext report and send the ciphertext report to the authority, wherein the bank asset data is the asset data of the target customer in the corresponding target response bank, and one target response bank generates one ciphertext report;

[0158] Step S204, controlling the above-mentioned authority to calculate the aggregated ciphertext according to all the above-mentioned ciphertext reports, generate an aggregated report and submit the above-mentioned aggregated report to the above-mentioned initiating bank;

[0159] Step S205, the initiating bank decrypts the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer based on the judgment result and execute the corresponding asset collection plan. The current overdue asset data is the overdue asset situation of the target customer at the initiating bank.

[0160] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order than here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0161] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0162] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0163] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0164] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0165] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0166] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0167] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0168] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0169] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0170] 1) The inter-bank collection asset verification method of the present application, first, controls the registration center to generate a symmetric homomorphic key, and sends the symmetric homomorphic key to the initiating bank and all responding banks, the registration center is used to initialize the key, the initiating bank is the bank that initiates the inter-bank asset verification request, the responding bank is the bank that signs and participates in the inter-bank collection asset verification agreement other than the initiating bank, the inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer, the inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data; then, the initiating bank sends the inter-bank asset verification request to the authority, so that the authority randomly selects the chaos factor and sends the chaos factor to the initiating bank and the target response bank, the target response bank is the response bank that owns the target customer; then, controls The above-mentioned target response bank calculates the ciphertext based on the bank asset data of the above-mentioned target customer according to the above-mentioned symmetric homomorphic key, generates a corresponding ciphertext report and sends the above-mentioned ciphertext report to the above-mentioned authoritative institution, the above-mentioned bank asset data is the asset data of the above-mentioned target customer in the corresponding above-mentioned target response bank, and one above-mentioned target response bank generates one above-mentioned ciphertext report; then, the above-mentioned authoritative institution is controlled to calculate the aggregated ciphertext according to all the above-mentioned ciphertext reports, generate an aggregated report and submit the above-mentioned aggregated report to the above-mentioned initiating bank; finally, the above-mentioned initiating bank decrypts according to the above-mentioned aggregated report to obtain the decrypted asset data, and compares and judges the above-mentioned decrypted asset data with the current overdue asset data of the above-mentioned target customer to obtain a judgment result, so as to verify the total asset situation of the above-mentioned target customer according to the above-mentioned judgment result and execute the corresponding asset collection plan, the above-mentioned current overdue asset data is the overdue and unpaid asset situation of the above-mentioned target customer in the above-mentioned initiating bank. This application is divided into five stages: the registration center key generation stage: the registration center generates a symmetric homomorphic key and sends it securely to the initiating bank and the responding bank; the initiating bank application and authority initialization stage: the initiating bank applies to the authority to view the cross-bank asset situation of a certain customer, and the authority randomly selects the chaotic factor and sends it to the corresponding responding bank in secret; the responding bank ciphertext generation stage: the responding bank calculates the ciphertext based on the customer's asset data in its own bank and sends the ciphertext report to the authority; the authority ciphertext aggregation stage: after receiving the ciphertext report from each responding bank, the authority calculates the aggregated ciphertext and submits it to the initiating bank; the initiating bank ciphertext decryption stage: after receiving the aggregated report from the authority, the initiating bank decrypts the aggregated report and compares the customer's asset data in its own bank with the decrypted data to verify the customer's asset situation. Prepare for the next deduction action. This move fills the possible cross-bank deduction loopholes, improves the collection mechanism, and provides data support for possible legal proceedings, providing a new solution for cross-bank collection.This application solves the problem in the prior art that mutual trust between multiple banks is difficult to achieve and there is a risk of cross-bank privacy leakage of customer data, so that banks cannot know all the asset situations of target customers, resulting in the inability to effectively collect assets across banks.

[0171] 2) The inter-bank collection asset verification device of the present application, the first control unit is used to control the registration center to generate a symmetric homomorphic key and send the above symmetric homomorphic key to the initiating bank and all responding banks, the above registration center is used to initialize the key, the above initiating bank is the bank that initiates the inter-bank asset verification request, the above responding bank is the bank that signs and participates in the inter-bank collection asset verification agreement other than the above initiating bank, the above inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer, and the above inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data; the initiating unit is used for the above initiating bank to send the above inter-bank asset verification request to the authority, so that the above authority randomly selects the chaos factor and sends the above chaos factor to the above initiating bank and the target response bank, and the above target response bank is the above response bank that owns the above target customer; the second control unit is used The target response bank is used to control the target customer's bank asset data to calculate the ciphertext according to the symmetric homomorphic key, generate the corresponding ciphertext report and send the ciphertext report to the authoritative institution. The bank asset data is the asset data of the target customer in the corresponding target response bank, and one target response bank generates one ciphertext report. The third control unit is used to control the authoritative institution to calculate the aggregated ciphertext according to all the ciphertext reports, generate the aggregated report and submit the aggregated report to the initiating bank. The decryption unit is used for the initiating bank to decrypt according to the aggregated report to obtain the decrypted asset data, and compare the decrypted asset data with the target customer's current overdue asset data to obtain a judgment result, so as to verify the total asset situation of the target customer and execute the corresponding asset collection plan according to the judgment result. The current overdue asset data is the overdue asset situation of the target customer in the initiating bank. This application is divided into five stages: the registration center key generation stage: the registration center generates a symmetric homomorphic key and securely sends it to the initiating bank and the responding bank; the initiating bank application and authority initialization stage: the initiating bank applies to the authority to view the cross-bank asset situation of a certain customer, and the authority randomly selects the chaotic factor and sends it to the corresponding responding bank in secret; the responding bank ciphertext generation stage: the responding bank calculates the ciphertext based on the customer's asset data in its own bank and sends the ciphertext report to the authority; the authority ciphertext aggregation stage: after receiving the ciphertext report from each responding bank, the authority calculates the aggregated ciphertext and submits it to the initiating bank; the initiating bank ciphertext decryption stage: after receiving the aggregated report from the authority, the initiating bank decrypts the aggregated report and compares the customer's asset data in its own bank with the decrypted data to verify the customer's asset situation. Prepare for the next deduction action.This move fills the possible loopholes in inter-bank deductions, improves the collection mechanism, provides data support for possible legal proceedings, and provides a new solution for inter-bank collection. This application solves the problem that it is difficult to achieve mutual trust between multiple banks in the prior art, and there is a risk of cross-bank privacy leakage of customer data, so that banks cannot know all the assets of the target customers, resulting in the inability to effectively collect assets across banks.

[0172] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for verifying assets for inter-bank collection, characterized in that: include: The control registration center generates a symmetric homomorphic key and sends the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is a bank that has signed and participated in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data; The initiating bank sends the inter-bank asset verification request to an authority, so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target responding bank, wherein the target responding bank is the responding bank that has the target customer; Control the target response bank to calculate the ciphertext according to the symmetric homomorphic key based on the bank asset data of the target customer, generate a corresponding ciphertext report and send the ciphertext report to the authority, wherein the bank asset data is the asset data of the target customer in the corresponding target response bank, and one target response bank generates one ciphertext report; Control the authority to calculate the aggregated ciphertext based on all the ciphertext reports, generate an aggregated report and submit the aggregated report to the initiating bank; The initiating bank decrypts the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer and execute the corresponding asset collection plan based on the judgment result. The current overdue asset data is the overdue asset situation of the target customer at the initiating bank.

2. The method according to claim 1, characterized in that: Control the registration center to generate symmetric homomorphic keys, including: Control the registration center to select a first prime number, a second prime number, a first random parameter, and a ciphertext level, and calculate a public parameter according to the product of the first prime number and the second prime number, wherein the first prime number is greater than the second prime number; and generate the symmetric homomorphic key according to the second prime number, the first random parameter, and the ciphertext level.

3. The method according to claim 1, characterized in that The initiating bank sends the inter-bank asset verification request to an authority, so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target response bank, including: The initiating bank sends the inter-bank asset verification request to the authoritative institution to apply for checking the inter-bank asset status of the target customer, so that the authoritative institution queries the corresponding responding bank according to the inter-bank asset verification request to obtain the target responding bank; Control the authority to randomly select the chaos factor k i , and sends the chaotic factor to the corresponding response bank, the chaotic factor satisfies k1+k2+…+k i +…+k n =0 mod N.

4. The method according to claim 1, characterized in that: Controlling the registration center to select a first prime number, a second prime number, a first random parameter, and a ciphertext level, and calculating a public parameter according to the product of the first prime number and the second prime number, controlling the target response bank to calculate a ciphertext according to the symmetric homomorphic key based on the bank asset data of the target customer, generating a corresponding ciphertext report and sending the ciphertext report to the authority, including: Controlling the target response bank to obtain plain text according to the bank asset data of the target customer in its own bank, and selecting a second random parameter, wherein the sum of the absolute value of the second random parameter and the absolute value of the second prime number is smaller than the absolute value of the public parameter; Control the target response bank to calculate the ciphertext using the symmetric homomorphic key and the plaintext according to a first formula, where the first formula is C i =s d (r i q+m i +k i )modN,C i represents the ciphertext of the i-th target response bank, s represents the first random parameter, d represents the ciphertext level, r i represents the second random parameter selected by the i-th target response bank, m i represents the plaintext obtained by the i-th target response bank, k i represents the chaos factor sent to the i-th target response bank, and N represents the public parameter; The target response bank is controlled to generate the ciphertext report according to the ciphertext, and the ciphertext report is sent to the authority, wherein the ciphertext report includes a current timestamp, the ciphertext and an identity of the target response bank.

5. The method according to claim 1, characterized in that Controlling the authority to calculate the aggregated ciphertext according to all the ciphertext reports, generate an aggregated report and submit the aggregated report to the initiating bank, including: Control the authority to receive all the ciphertext reports and calculate the aggregate ciphertext according to a second formula, wherein the second formula is C=C1+C2+…+C i +…+C n mod N,C i represents the ciphertext of the i-th target response bank, and C represents the aggregated ciphertext; The authoritative institution is controlled to generate the aggregate report according to the aggregate ciphertext, and the aggregate report is sent to the initiating bank, wherein the ciphertext report includes a current timestamp, the aggregate ciphertext and an identity identifier of the authoritative institution.

6. The method according to claim 1, characterized in that The judgment result is that the target customer has fully repayable assets, or the target customer has partially repayable assets, or the target customer has no assets. The fully repayable assets indicate that the total assets of the target customer in all the target response banks can repay all the debts owed to the initiating bank, and the partially repayable assets indicate that the total assets of the target customer in all the target response banks cannot fully repay all the debts owed to the initiating bank. The initiating bank decrypts the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, including: After receiving the aggregate report sent by the authoritative institution, the initiating bank uses the homomorphic encryption key to perform decryption using a symmetric homomorphic encryption algorithm according to the aggregate report to obtain the decrypted asset data; Comparing the decrypted asset data with the current overdue asset data; In the case where the decrypted asset data is greater than or equal to the current overdue asset data, determining that the judgment result is that the target customer has the fully repayable assets; In the case where the decrypted asset data is less than the current overdue asset data and the decrypted asset data is greater than zero, it is determined that the determination result is that the target customer has partially repayable assets; When the decrypted asset data is less than or equal to zero, it is determined that the determination result is that the target customer has no assets.

7. The method according to claim 6, characterized in that After the initiating bank decrypts the aggregate report to obtain decrypted asset data, and compares the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, the method further includes: When the judgment result is that the target customer has the fully repayable assets or the judgment result is that the target customer has the partially repayable assets, the asset collection plan is determined to be inter-bank deductions executed through court litigation.

8. An inter-bank collection asset verification device, characterized in that: The device comprises: A first control unit is used to control the registration center to generate a symmetric homomorphic key and send the symmetric homomorphic key to the initiating bank and all responding banks. The registration center is used to initialize the key. The initiating bank is the bank that initiates the inter-bank asset verification request. The responding bank is a bank that has signed and participated in the inter-bank collection asset verification agreement other than the initiating bank. The inter-bank asset verification request is used to apply to view the inter-bank asset status of the target customer. The inter-bank collection asset verification agreement is an agreement to share asset data to verify customer assets under the premise of ensuring the privacy of bank customer data; An initiating unit, configured for the initiating bank to send the inter-bank asset verification request to an authority, so that the authority randomly selects a chaotic factor and sends the chaotic factor to the initiating bank and a target responding bank, wherein the target responding bank is the responding bank that has the target customer; A second control unit is used to control the target response bank to calculate the ciphertext according to the symmetric homomorphic key based on the bank asset data of the target customer, generate a corresponding ciphertext report and send the ciphertext report to the authority, wherein the bank asset data is the asset data of the target customer in the corresponding target response bank, and one target response bank generates one ciphertext report; A third control unit, configured to control the authority to calculate the aggregated ciphertext according to all the ciphertext reports, generate an aggregated report and submit the aggregated report to the initiating bank; A decryption unit is used for the initiating bank to decrypt according to the aggregate report to obtain decrypted asset data, and compare and judge the decrypted asset data with the current overdue asset data of the target customer to obtain a judgment result, so as to verify the total asset situation of the target customer according to the judgment result and execute the corresponding asset collection plan, wherein the current overdue asset data is the overdue asset situation of the target customer at the initiating bank.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 7.

10. A computer program product comprising computer instructions, characterized in that When the computer instructions are executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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