Cross-institutional blacklist sharing method and system based on reusable obfuscation circuits

Abstract

The present invention discloses a cross-institutional blacklist sharing method and system based on reusable obfuscation circuits, relating to the field of privacy computing. Specifically, the cross-institutional blacklist sharing method based on reusable obfuscation circuits involves uploading multi-party blacklist data to a blockchain trusted environment in ciphertext form. Three obfuscation techniques are then used to convert the circuits into reusable obfuscated circuits, enabling the obfuscated circuits to be reused, significantly reducing communication overhead. Finally, the data encryption and oblivious transmission process of the reusable obfuscation circuits are utilized to ensure the reliable and confidential execution of computing tasks. The cross-institutional blacklist sharing method based on reusable obfuscation circuits effectively protects data privacy from abuse and enhances the feasibility and effectiveness of cross-institutional blacklist data applications.

Description

Technical Field

[0001] The present invention belongs to the field of privacy computing, and specifically relates to a cross-institutional blacklist sharing method and system based on reusable obfuscation circuits. Background Art

[0002] Blacklists are primarily used to record misconduct by individual or corporate clients. Each institution maintains blacklists for various services, which serve as crucial entry criteria for financial institutions in areas such as account opening, credit, wealth management, and funding. Sharing and querying blacklists between financial institutions helps mitigate risks such as multiple lending, bill fraud, and money laundering. However, sharing blacklists in plain text compromises user privacy and leaks commercial secrets.

[0003] Obfuscated circuits are a protocol for performing two-party secure computation at the circuit level and are also a secure multi-party computation protocol with low computational cost. Due to the universality of using circuits to describe computational tasks, obfuscated circuits have broad applicability; any computational task that can be represented using circuits can be solved using obfuscated circuits. While obfuscated circuits offer the advantages of low computational cost, independent communication times and circuit scale, and strong applicability, they also suffer from the disadvantage of being difficult to reuse. Therefore, we introduce a reusable obfuscated circuit approach, which allows the querying party to re-enter the obfuscated circuit multiple times. Compared to traditional obfuscated circuits, reusable obfuscated circuits significantly reduce communication overhead. Furthermore, reusable obfuscated circuits enable party A to send obfuscated data to an untrusted party B, ensuring that the shared data is not leaked and can only be used for the intended purpose implemented by the original circuit. This effectively protects data privacy from misuse while efficiently completing the computational task.

[0004] The inquiring party uses hidden query technology to ensure that when submitting a calculation or query task request, the calculation or query task is completed under the premise that the query information is not perceived or leaked, thereby ensuring the data privacy of all parties involved and improving the feasibility and effectiveness of cross-institutional blacklist data application. Summary of the Invention

[0005] Based on the above background and problems existing in the prior art, the present invention adopts the following technical solutions: First, a cross-institutional blacklist sharing method based on reusable obfuscation circuits is provided, which can utilize reusable obfuscation circuits to use obfuscation technology to confuse data, thereby realizing cross-institutional blacklist sharing and protecting the privacy of data from being leaked.

[0006] A cross-institutional blacklist sharing method based on reusable obfuscation circuits is implemented in a blockchain trusted environment. The method includes the following steps:

[0007] Obtain the private data of the data provider and the queryer, where the private data is the blacklist data in ciphertext form;

[0008] Constructing a Boolean circuit and converting the Boolean circuit to obtain a reusable obfuscated circuit;

[0009] Generate a pair of random keys for the first input signal, the second input signal and the output signal of each gate of the reusable obfuscation circuit respectively;

[0010] Iteratively encrypt the output signal based on the random key to obtain an encryption table, and scramble the rows of the encryption table to obtain an obfuscation table;

[0011] Obtaining a selected bit random key corresponding to the second input signal based on the random key corresponding to the first input signal and the random key corresponding to the second input signal;

[0012] Decrypting the obfuscation table based on the selected random key corresponding to the second input signal and the private data of the querying party to obtain an output result in the form of a key;

[0013] The key-formatted output result is decrypted to obtain a plaintext output result.

[0014] As an implementation method, the random keys corresponding to the first input signals are and The random keys corresponding to the second input signal are and The random keys corresponding to the output signals are and

[0015] As an implementable method, converting the Boolean circuit to obtain a reusable obfuscation circuit includes the following steps:

[0016] Performing bit flipping on all gates in the Boolean circuit and the first input signal to obtain a reusable garbled circuit and a garbled input to achieve indistinguishable obfuscation of balanced gates in the reusable garbled circuit, wherein the balanced gates include XOR gates and XOR gates;

[0017] Identifying fixed gates in a reusable obfuscation circuit and achieving indistinguishable obfuscation of the fixed gates in the reusable obfuscation circuit, wherein the fixed gates are gates that return the same value for a given first input signal;

[0018] Identify all intermediate gates in the reusable garbled circuit, where the intermediate gates represent gates between the first layer of the reusable garbled circuit and the associated fixed gates;

[0019] All unbalanced gates, fixed gates and middle gates on the first layer are randomly aliased into XOR gates or XNOR gates to provide indistinguishable obfuscation and obtain the truth table of the reusable aliased circuit.

[0020] As an implementation method, the bit flipping includes the following steps:

[0021] applying a flip to all input bits of the first input signal and all lines of the Boolean circuit to obtain a reusable garbled circuit and garbled input;

[0022] When the output line of the reusable garbled circuit is flipped, the truth table of the output line sub-gate is modified to restore the integrity of the reusable garbled circuit.

[0023] As an implementable method, the method of identifying fixed gates in a reusable obfuscation circuit and achieving indistinguishable obfuscation of the fixed gates in the reusable obfuscation circuit includes the following steps:

[0024] Identifying all fixed gates in the reusable garbled circuit;

[0025] Randomly select a row of the truth table of a fixed gate and flip the output line corresponding to the row to confuse the fixed gate;

[0026] The truth table is adjusted to restore the integrity of the reusable garbled circuit, all sub-gates of the fixed gate in the reusable garbled circuit are modified into fixed gates and iterated to obtain a more optimized reusable garbled circuit.

[0027] As an implementable method, the iterative encryption of the output signal based on the random key to obtain an encryption table includes the following steps:

[0028] Generate a public key and a private key based on a key generation function, and send the private key to the blockchain trusted environment;

[0029] Based on the given public key, the target plaintext data is encrypted through the encryption function to obtain the ciphertext;

[0030] Based on the encryption process, the encryption table is obtained by iterating multiple times.

[0031] As an implementable method, the following steps are also included:

[0032] The random key or Send to the blockchain trusted environment;

[0033] The blockchain trusted environment is constructed by selecting a bit m∈{0,1} and combining it with a random key and Get the selected random key

[0034] A cross-institutional blacklist sharing system based on reusable obfuscation circuits includes a data acquisition module, a reusable obfuscation circuit construction module, a key construction module, and a decryption output module;

[0035] The data acquisition module is used to acquire the private data of the data provider and the private data of the query party, wherein the private data is the blacklist data in ciphertext form;

[0036] The reusable obfuscation circuit construction module is used to construct a Boolean circuit and convert the Boolean circuit to obtain a reusable obfuscation circuit; generate a pair of random keys for the first input signal, the second input signal, and the output signal of each gate of the reusable obfuscation circuit; iteratively encrypt the output signal based on the random keys to obtain an encryption table, and shuffle the rows of the encryption table to obtain an obfuscation table;

[0037] The key construction module obtains a selected bit random key corresponding to the second input signal based on the random key corresponding to the first input signal and the random key corresponding to the second input signal;

[0038] The decryption output module decrypts the obfuscation table based on the selected bit random key corresponding to the second input signal and the query party's private data to obtain a key-form output result; and decrypts the key-form output result to obtain a plaintext output result.

[0039] A computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements any one of the following methods:

[0040] Obtain the private data of the data provider and the queryer, where the private data is the blacklist data in ciphertext form;

[0041] Constructing a Boolean circuit and converting the Boolean circuit to obtain a reusable obfuscated circuit;

[0042] Generate a pair of random keys for the first input signal, the second input signal and the output signal of each gate of the reusable obfuscation circuit respectively;

[0043] Iteratively encrypt the output signal based on the random key to obtain an encryption table, and scramble the rows of the encryption table to obtain an obfuscation table;

[0044] Obtaining a selected bit random key corresponding to the second input signal based on the random key corresponding to the first input signal and the random key corresponding to the second input signal;

[0045] Decrypting the obfuscation table based on the selected random key corresponding to the second input signal and the private data of the querying party to obtain an output result in the form of a key;

[0046] The key-formatted output result is decrypted to obtain a plaintext output result.

[0047] A cross-organization blacklist sharing device based on a reusable obfuscation circuit includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the following method is implemented:

[0048] Obtain the private data of the data provider and the queryer, where the private data is the blacklist data in ciphertext form;

[0049] Constructing a Boolean circuit and converting the Boolean circuit to obtain a reusable obfuscated circuit;

[0050] Generate a pair of random keys for the first input signal, the second input signal and the output signal of each gate of the reusable obfuscation circuit respectively;

[0051] Iteratively encrypt the output signal based on the random key to obtain an encryption table, and scramble the rows of the encryption table to obtain an obfuscation table;

[0052] Obtaining a selected bit random key corresponding to the second input signal based on the random key corresponding to the first input signal and the random key corresponding to the second input signal;

[0053] Decrypting the obfuscation table based on the selected random key corresponding to the second input signal and the private data of the querying party to obtain an output result in the form of a key;

[0054] The key-formatted output result is decrypted to obtain a plaintext output result.

[0055] The present invention has at least the following beneficial effects:

[0056] (1) A cross-institutional blacklist sharing method and system based on reusable obfuscation circuits is proposed. Reusable obfuscation circuits are used to obfuscate data using information theory techniques. The same obfuscation circuit can be reused multiple times with any input, significantly reducing communication overhead.

[0057] (2) A cross-institutional blacklist sharing method and system based on reusable obfuscation circuits is proposed. The hidden query technology provided by the reusable obfuscation circuits is used to ensure that when a calculation or query task request is submitted, the query and calculation are completed under the premise that the query information is not perceived or leaked, thereby ensuring the data privacy of all parties involved and improving the feasibility and effectiveness of cross-institutional blacklist applications.

[0058] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1Schematic diagram of the cross-institutional blacklist sharing method based on reusable obfuscation circuits of the present invention

[0060] Figure 2 Schematic diagram of the gate circuit in the garbled circuit of the present invention

[0061] Figure 3 Schematic diagram of the garbled circuit of the present invention

[0062] Figure 4 This is an example diagram of the transmission process of the garbled circuit of the present invention DETAILED DESCRIPTION

[0063] In order to clearly explain the present invention and make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below in combination with the drawings in the embodiments of the present invention, so that those skilled in the art can implement them according to the text of the description.

[0064] In the context of the present invention, a trusted execution environment (TEE) provides an isolated runtime environment from the perspective of the underlying hardware and operating system, protecting the code and data running within it from external attacks, including attacks from the operating system, hardware, and other applications. This technology has been used in some fields to achieve the objectives described above, and some of the basic principles of this technology are also known to those skilled in the art. However, after reading this application, those skilled in the art will understand how to apply this technology in this context and will clearly understand the novelty of this technology when combined with other features in a specific context.

[0065] The technology of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0066] Example 1:

[0067] The present invention is a cross-organization blacklist sharing method based on reusable obfuscation circuits. The steps of the invention are shown in the following figure: Figure 1 The specific steps are as follows:

[0068] (1) Obtain the private data of the data provider and the private data of the querying party, wherein the private data is the blacklist data in ciphertext form.

[0069] (2) Constructing a Boolean circuit C and converting the Boolean circuit into a reusable obfuscated circuit C′ using three obfuscation techniques, including the following steps:

[0070] Performing bit flipping on all gates in the Boolean circuit C and the first input signal x to obtain a reusable garbled circuit C′ and a garbled input x′, so as to achieve indistinguishable obfuscation of balanced gates in the reusable garbled circuit C′, wherein the balanced gates include XOR gates and XOR gates;

[0071] The bit flipping comprises the following steps:

[0072] Applying a flip once to all input bits of a first input signal x and all lines of a Boolean circuit C to obtain a reusable garbled circuit C′ and a garbled input x′, wherein the first input signal x includes: a left input u and a right input v;

[0073] Whenever the output line w is flipped, the query party needs to modify the truth table of the w sub-gate to restore the integrity of the reusable garbled circuit C′. For example, if the left input line of the gate g with function w = f(u,v) is flipped, we can modify the truth table of g′ to To ensure that C′(x′,y)=C(x,y). Two identical truth tables can be constructed by different inputs and bit flipping, so the blockchain trusted environment cannot infer the querying party’s input by checking the truth table of the balancing gate that the querying party may flip.

[0074] Identifying fixed gates in a reusable obfuscation circuit C′ and achieving indistinguishable obfuscation of the fixed gates in the reusable obfuscation circuit C′, wherein the fixed gates are gates that return the same value given a first input signal x;

[0075] The step of identifying fixed gates in the reusable obfuscation circuit C′ and achieving indistinguishable obfuscation of the fixed gates in C′ comprises the following steps:

[0076] Identifying all fixed gates in the reusable garbled circuit C′;

[0077] Randomly select a row of the truth table of a fixed gate and flip the output line corresponding to the row to confuse the fixed gate;

[0078] The truth table is adjusted to restore the integrity of the reusable garbled circuit C′, and all sub-gates of the fixed gates in the reusable garbled circuit C′ are modified into fixed gates to obtain a more optimized reusable garbled circuit.

[0079] Identify all intermediate gates in the reusable garbled circuit C′, where an intermediate gate represents a gate between the first layer of the reusable garbled circuit and the associated fixed gate;

[0080] All unbalanced gates, fixed gates, and intermediate gates on the first layer are randomly confused with XOR gates or XNOR gates to provide indistinguishable confusion, and the truth table of the reusable confusion circuit is obtained, as shown in Figure 3 As shown in a.

[0081] (3) Generate a pair of random keys for the first input signal, the second input signal and the output signal of each gate of the reusable obfuscation circuit, such as Figure 2 As shown in the figure, the key correspondence between the first input signal, the second input signal and the output signal of the AND gate is obtained, and the key table is obtained, as shown in the figure. Figure 3As shown in b, the random keys corresponding to the first input signal x are and The random keys corresponding to the second input signal y are and The random keys corresponding to the output signal z are and

[0082] (4) Iteratively encrypt the output signal based on the random key to obtain an encryption table, such as Figure 3 c, including the following steps:

[0083] After the encryption parameter λ is given, the public key pk and private key sk are generated based on the key generation function KeyGen(), and the private key is sent to the blockchain trusted environment;

[0084] Key generation function: KeyGen(λ)→(pk,sk)

[0085] Based on the given public key pk, the target plaintext data pt is encrypted by the encryption function Encrypt() to obtain the ciphertext ct;

[0086] Encryption function: Encrypt(pt,pk)→ct

[0087] Based on the encryption process, the encryption table is obtained by iterating multiple times.

[0088] The rows of the encryption table are shuffled to obtain a confusion table, such as Figure 3 d. The following is the transmission process of the obfuscated circuit. Assuming that the query party wire input is 0 and the blockchain trusted environment input is 1, we get Figure 4 The transmission process is shown.

[0089] (5) Based on the random key corresponding to the first input signal and the random key corresponding to the second input signal, obtaining a selected bit random key corresponding to the second input signal, including the following steps:

[0090] The random key or Send to the blockchain trusted environment;

[0091] The blockchain trusted environment is constructed by selecting a bit m∈{0,1} and combining it with a random key and Get the selected random key

[0092] (6) Decrypting the obfuscation table based on the selected bit random key corresponding to the second input signal and the private data of the querying party to obtain an output result in the form of a key.

[0093] The blockchain trusted environment uses the random key combination corresponding to the private data input of the query party and the private data input of the data provider to decrypt the obfuscation table through the decryption function Decrypt(), obtains the output result in the form of a key, and then sends the output result in the form of a key to the query party.

[0094] Decryption function: Decrypt(sk,ct)→pt

[0095] (7) Decrypt the key-based output result to obtain a plaintext output result.

[0096] In summary, the present invention provides a cross-institutional blacklist sharing method and system based on reusable obfuscation circuits. In this method, multi-party blacklist data is uploaded to a blockchain trusted environment in encrypted form. Three obfuscation techniques are then used to convert the circuits into reusable obfuscated circuits, enabling them to be reused, significantly reducing communication overhead. Finally, the reusable obfuscated circuits' data encryption and oblivious transmission processes ensure the reliable and confidential execution of computing tasks. This cross-institutional blacklist sharing method based on reusable obfuscation circuits effectively protects data privacy from abuse and enhances the feasibility and effectiveness of cross-institutional blacklist data applications.

[0097] Example 2:

[0098] A cross-institutional blacklist sharing system based on reusable obfuscation circuits includes a data acquisition module, a reusable obfuscation circuit construction module, a key construction module, and a decryption output module;

[0099] The data acquisition module is used to acquire the private data of the data provider and the private data of the query party, wherein the private data is the blacklist data in ciphertext form;

[0100] The reusable obfuscation circuit construction module is used to construct a Boolean circuit and convert the Boolean circuit to obtain a reusable obfuscation circuit; generate a pair of random keys for the first input signal, the second input signal, and the output signal of each gate of the reusable obfuscation circuit; iteratively encrypt the output signal based on the random keys to obtain an encryption table, and shuffle the rows of the encryption table to obtain an obfuscation table;

[0101] The key construction module obtains a selected bit random key corresponding to the second input signal based on the random key corresponding to the first input signal and the random key corresponding to the second input signal;

[0102] The decryption output module decrypts the obfuscation table based on the selected bit random key corresponding to the second input signal and the query party's private data to obtain a key-form output result; and decrypts the key-form output result to obtain a plaintext output result.

[0103] Various changes and modifications can be made without departing from the spirit and scope of the present invention, and all equivalent technical solutions also fall within the scope of the present invention.

[0104] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0105] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, apparatus, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0106] The present invention is described with reference to the flowcharts and / or block diagrams of the method, terminal device (system), and computer program product according to the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks 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 terminal device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the process 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.

[0107] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0108] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0109] It should be noted that:

[0110] References in this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Therefore, appearances of the phrases "one embodiment" or "an embodiment" in various places throughout this specification do not necessarily refer to the same embodiment.

[0111] The above description of the embodiments is intended to facilitate understanding and application of the present invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to the above embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention should fall within the scope of protection of the present invention.

Claims

1. A cross-institutional blacklist sharing method based on reusable obfuscation circuits, implemented in a blockchain trusted environment, characterized by: The method comprises the following steps: Obtain the private data of the data provider and the queryer, where the private data is the blacklist data in ciphertext form; Constructing a Boolean circuit and converting the Boolean circuit to obtain a reusable obfuscated circuit; Generate a pair of random keys for the first input signal, the second input signal and the output signal of each gate of the reusable obfuscation circuit respectively; Iteratively encrypt the output signal based on the random key to obtain an encryption table, and scramble the rows of the encryption table to obtain an obfuscation table; Obtaining a selected bit random key corresponding to the second input signal based on the random key corresponding to the first input signal and the random key corresponding to the second input signal; Decrypting the obfuscation table based on the selected random key corresponding to the second input signal and the private data of the querying party to obtain an output result in the form of a key; The key-formatted output result is decrypted to obtain a plaintext output result.

2. The cross-institutional blacklist sharing method based on reusable obfuscation circuits according to claim 1 is characterized in that: The random keys corresponding to the first input signals are and The random keys corresponding to the second input signal are and The random keys corresponding to the output signals are and 3. The cross-institutional blacklist sharing method based on reusable obfuscation circuits according to claim 1 is characterized in that: The step of converting the Boolean circuit to obtain a reusable obfuscation circuit comprises the following steps: Performing bit flipping on all gates in the Boolean circuit and the first input signal to obtain a reusable garbled circuit and a garbled input to achieve indistinguishable obfuscation of balanced gates in the reusable garbled circuit, wherein the balanced gates include XOR gates and XOR gates; Identifying fixed gates in a reusable obfuscation circuit and achieving indistinguishable obfuscation of the fixed gates in the reusable obfuscation circuit, wherein the fixed gates are gates that return the same value for a given first input signal; Identify all intermediate gates in the reusable garbled circuit, where the intermediate gates represent gates between the first layer of the reusable garbled circuit and the associated fixed gates; All unbalanced gates, fixed gates and middle gates on the first layer are randomly aliased into XOR gates or XNOR gates to provide indistinguishable obfuscation and obtain the truth table of the reusable aliased circuit.

4. The cross-institutional blacklist sharing method based on reusable obfuscation circuits according to claim 3 is characterized in that: The bit flipping comprises the following steps: applying a flip to all input bits of the first input signal and all wires in the Boolean circuit to obtain a reusable garbled circuit and garbled input; When the output line of the reusable garbled circuit is flipped, the truth table of the output line sub-gate is modified to restore the integrity of the reusable garbled circuit.

5. The cross-institutional blacklist sharing method based on reusable obfuscation circuits according to claim 3 is characterized in that: The method of identifying fixed gates in a reusable obfuscation circuit and achieving indistinguishable obfuscation of the fixed gates in the reusable obfuscation circuit comprises the following steps: Identifying all fixed gates in the reusable garbled circuit; Randomly select a row of the truth table of a fixed gate and flip the output line corresponding to the row to confuse the fixed gate; The truth table is adjusted to restore the integrity of the reusable garbled circuit, all sub-gates of the fixed gate in the reusable garbled circuit are modified into fixed gates and iterated to obtain a more optimized reusable garbled circuit.

6. The cross-institutional blacklist sharing method based on reusable obfuscation circuits according to claim 1 is characterized in that: The iterative encryption of the output signal based on the random key to obtain an encryption table comprises the following steps: Generate a public key and a private key based on a key generation function, and send the private key to the blockchain trusted environment; Based on the given public key, the target plaintext data is encrypted through the encryption function to obtain the ciphertext; Based on the encryption process, the encryption table is obtained by iterating multiple times.

7. The cross-institutional blacklist sharing method based on reusable obfuscation circuits according to claim 2 is characterized in that: The following steps are also included: The random key or Send to the blockchain trusted environment; The blockchain trusted environment is constructed by selecting a bit m∈{0,1} and combining it with a random key and Get the selected random key 8. A cross-institutional blacklist sharing system based on reusable obfuscation circuits, characterized in that: It includes a data acquisition module, a reusable obfuscation circuit construction module, a key construction module and a decryption output module; The data acquisition module is used to acquire the private data of the data provider and the private data of the query party, wherein the private data is the blacklist data in ciphertext form; The reusable obfuscation circuit construction module is used to construct a Boolean circuit and convert the Boolean circuit to obtain a reusable obfuscation circuit; generate a pair of random keys for the first input signal, the second input signal, and the output signal of each gate of the reusable obfuscation circuit; iteratively encrypt the output signal based on the random keys to obtain an encryption table, and shuffle the rows of the encryption table to obtain an obfuscation table; The key construction module obtains a selected bit random key corresponding to the second input signal based on the random key corresponding to the first input signal and the random key corresponding to the second input signal; The decryption output module decrypts the obfuscation table based on the selected bit random key corresponding to the second input signal and the query party's private data to obtain an output result in key form; and decrypts the output result in key form to obtain a plaintext output result.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. A cross-organization blacklist sharing device based on a reusable obfuscation circuit, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

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