Pseudo-random function-based privacy information retrieval protocol construction method, system and equipment and medium

Abstract

A method, system, device and medium for constructing a privacy information retrieval protocol based on a pseudo-random function, the method comprising: first initializing the system, setting a security parameter and a hash function, and performing casual pseudo-random function encryption based on the security parameter and the hash function to obtain a matrix; the method comprises the following steps of: acquiring a security parameter, performing casual transmission on the basis of the security parameter, a hash function and a matrix to obtain a hash function value, packaging the hash function value by a data service platform, constructing a packaging function, confusing the packaging function by using undistinguishable confusion to obtain a confusion function, and finally calculating retrieval data by using a pseudo-random function. And inputting the information into the obfuscation function for retrieval, thereby hiding the retrieval information. The system, the equipment and the medium are used for implementing the method. According to the method, the user privacy can be protected under the quantum attack, the calculation complexity is reduced, meanwhile, malicious users can be prevented from attempting to know other data, and the effects of low calculation cost and high data security are achieved.

Description

Technical Field

[0001] The present invention relates to the field of data security technology, and in particular to a construction method, system, device and medium for a privacy information retrieval protocol based on a pseudo-random function. Background Art

[0002] As an important cryptographic protocol, Private Information Retrieval (PIR) has attracted increasing attention in privacy computing. However, existing PIR protocols usually do not consider the threat of future quantum computers. As a related protocol of PIR, there are some post-quantum designs of private set intersection protocols, but the computational complexity of these protocols is at least O(mnlog(mn)), where m is the modulus of the encryption algorithm operation and n is the dimension of the encryption algorithm operation.

[0003] Chase et al. published Private Set Intersection in the Internet Setting From Lightweight Oblivious PRF (Chase, M., Miao, P. Private Set Intersection in the Internet Setting From Lightweight Oblivious PRF[J]. Advances in Cryptology–CRYPTO 2020, 2020, 2020: 34–63.), presenting a lightweight two-party private intersection protocol, but due to the limitations of the protocol structure, it cannot resist quantum attacks. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a method, system, device and medium for constructing a privacy information retrieval protocol based on a pseudo-random function, and to construct post-quantum privacy information retrieval through an inadvertent pseudo-random function, so as to solve the threat of future quantum computers and secondly reduce the computational complexity to O(nlog(n)).

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for constructing a privacy information retrieval protocol based on a pseudo-random function comprises the following steps:

[0007] Step 1: Initialize the system and set the security parameters m, w, and hash functions and

[0008] Step 2: Based on the security parameters m,w, set in step 1 and hash functions and Perform random pseudo-random function encryption to obtain matrix D;

[0009] Step 3: Based on the security parameters m,w, set in step 1 Hash functions and The matrix D obtained in step 2 is inadvertently transferred to obtain the hash function value h;

[0010] Step 4: Data Service Platform P s Package the hash function value h obtained in step 3, construct a wrapper function, and then use indistinguishable obfuscation to obfuscate the wrapper function to obtain an obfuscated function

[0011] Step 5: Use a pseudo-random function to calculate the retrieved data and input it into the obfuscation function obtained in step 4. The search is performed in the search, thereby hiding the search information.

[0012] The step 1 is specifically as follows:

[0013] Set the security parameters of the protocol Represents a set of integers and sets three hash functions and in, Represents a univariate polynomial ring

[0014] The step 2 is specifically as follows:

[0015] Data Service Platform s Select the pseudo-random function key Send the pseudo-random function key k to user P u , data service platform P s Input private data to the pseudo-random function Calculate the pseudorandom function value v:

[0016]

[0017] Where F represents a pseudo-random function, is the function for hashing the private data x, is a pseudo-random function based on the key k, For a pseudo-random function The hash function is processed twice and once by a pseudo-random function. u The obtained pseudo-random function value v is a result with privacy protection characteristics. The pseudo-random function value v combines the privacy data with the characteristics of the pseudo-random function.

[0018] Convert the pseudo-random function value v into a matrix, data service platform P s Assume the initial matrix D = 1 m×w , where D is an m×w matrix with each component equal to 1, and D i [v[i]]=0, that is, change the v[i]th element of the i-th row to 0, thus obtaining a new matrix D∈{0,1} m×w .

[0019] The step three is specifically as follows:

[0020] Step 3.1, Data Service Platform P s Execution: Data Service Platform P s Sending bits s[1],...,s[w]∈{0,1}, user P u The column vector {r i (0) ,r i (1)} i∈[w] , data service platform P s The column vector {r i} i∈[w] , where r i (0) +r i (1) =1 m ,r i =r i s[i] ∈{0,1} m ;

[0021] Step 3.2, User P u Execution: User P u The column vector {r i (0) ,r i (1)} i∈[w] And combined into a matrix And calculate the matrix and column vector i∈[w] and the column vector Δ i Send to P s ;

[0022] Step 3.3, Data Service Platform P s Execution: Data Service Platform P sReceive the column vector Δ sent in step 3.2 i Then calculate C, that is: when s[i] = 0, then C i =r i ;otherwise Output hash function value Here, s[i] represents the i-th bit of s.

[0023] The step 4 is specifically as follows:

[0024] Data Service Platform s Pack the hash function value h and construct a wrapper function:

[0025] ψ(h)=ψ(x)=ψ1(h)+ψ2(h),

[0026] Wherein, ψ1(h)=0, ψ2(h)=message, message is the message corresponding to the pseudo-random function value h;

[0027] Then use indistinguishable obfuscation to obfuscate the encapsulated function and get the obfuscated function And the obfuscation function Send to user P u .

[0028] The step five is specifically as follows:

[0029] User P u Encrypt the content y to be retrieved using a pseudo-random function to obtain a pseudo-random function value v:

[0030]

[0031] User P u Assume the initial matrix E∈1 m×w , where each component of the m×w matrix is ​​1, and let E i [v[i]]=0, that is, change the u[i]th element in the i-th row to 0, thus obtaining a new E∈{0,1} m×w , user P u Calculate the hash function value l associated with y, that is v1‖v2=(v1,v2);

[0032] User P u Confusion Function Enter search data The corresponding hash function value When user P u Retrieval data When , the confusion function The output is empty, which means the search failed. u Retrieval data When , the confusion function The output is the hash function value The corresponding message is displayed, indicating that the retrieval is successful.

[0033] A system for constructing a privacy information retrieval protocol based on an oblivious pseudo-random function, comprising:

[0034] System initialization module, system initialization, setting security parameters m, w, and hash functions and

[0035] The oblivious transmission preparation module is based on the security parameters m,w, and hash functions and Perform random pseudo-random function encryption to obtain matrix D;

[0036] The random pseudo-random function encryption module is based on the security parameters m,w, Hash functions and And matrix D is obliviously transferred to obtain the hash function value h;

[0037] Data packaging module, data service platform P s Pack the hash function value h into data, construct the encapsulation function, and then use indistinguishable obfuscation to confuse the encapsulation function to obtain the obfuscated function

[0038] The user retrieval module uses a pseudo-random function to calculate the retrieval data and inputs it into the obfuscation function The search is performed in the search, thereby hiding the search information.

[0039] A device for constructing a privacy information retrieval protocol based on an oblivious pseudo-random function, comprising:

[0040] Memory: used for storing a computer program for implementing a construction method of a privacy information retrieval protocol based on an oblivious pseudo-random function;

[0041] Processor: used to implement a construction method of a privacy information retrieval protocol based on an inadvertent pseudo-random function when executing the computer program.

[0042] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for constructing a privacy information retrieval protocol based on an inadvertent pseudo-random function.

[0043] Compared with the prior art, the beneficial effects of the present invention are:

[0044] 1. The present invention adopts three hash functions and a pseudo-random function to construct a private information retrieval protocol, thereby achieving user privacy protection, resisting quantum attacks, and reducing computational complexity, and has the effects of post-quantum security and low computational cost.

[0045] 2. The present invention utilizes indistinguishable obfuscation to protect encapsulation functions, realizes hiding of data inside the encapsulation function, and has the capability to prevent malicious users from attempting to learn other data, thereby improving data security. Meanwhile, the data service platform converts all data into hash function values, encapsulates the hash function values ​​with encapsulation functions, and obfuscates the encapsulation functions with indistinguishable obfuscation to obtain obfuscated functions and sends them to users. Therefore, the data service platform cannot know the user's search information, thereby protecting the user's privacy and further improving data security.

[0046] In summary, the privacy information retrieval protocol of the present invention can protect user privacy and reduce computational complexity under quantum attacks, while preventing malicious users from attempting to understand other data, and has the effects of low computational cost and high data security. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a functional schematic diagram of the present invention.

[0048] Figure 2 It is an operational structure diagram of the present invention.

[0049] Figure 3 It is a simulation comparison diagram of the present invention. DETAILED DESCRIPTION

[0050] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0051] A method for constructing a privacy information retrieval protocol based on a pseudo-random function comprises the following steps:

[0052] Step 1: Initialize the system and set the security parameters m, w, and hash functions and

[0053] Step 2: Based on the security parameters m,w, set in step 1 and hash functions and Perform random pseudo-random function encryption to obtain matrix D;

[0054] Step 3: Based on the security parameters m,w, set in step 1 Hash functions and The matrix D obtained in step 2 is inadvertently transferred to obtain the hash function value h;

[0055] Step 4: Data Service Platform P s Package the hash function value h obtained in step 3, construct a wrapper function, and then use indistinguishable obfuscation to obfuscate the wrapper function to obtain an obfuscated function

[0056] Step 5: Use a pseudo-random function to calculate the retrieved data and input it into the obfuscation function obtained in step 4. The search is performed in the search, thereby hiding the search information.

[0057] The step 1 is specifically as follows:

[0058] Set the security parameters of the protocol Represents a set of integers and sets three hash functions and in, Represents a univariate polynomial ring

[0059] The step 2 is specifically as follows:

[0060] Data Service Platform s Select the pseudo-random function key Send the pseudo-random function key k to user P u , data service platform P s Input private data to the pseudo-random function Calculate the pseudorandom function value v:

[0061]

[0062] Where F represents a pseudo-random function, is the function for hashing the private data x, is a pseudo-random function based on the key k, For a pseudo-random function The hash function is processed twice and once by a pseudo-random function. u The obtained pseudo-random function value v is a result with privacy protection characteristics, which combines the privacy data with the characteristics of the pseudo-random function. In addition, It is a {0,1}-NTRU problem. Based on the {0,1}-NTRU problem, a post-quantum oblivious pseudo-random function is constructed. The {0,1}-NTRU problem refers to any turn up Make This is a classic lattice theory problem, which has been proven to be resistant to quantum attacks. Therefore, it is not difficult to prove that the inadvertent pseudo-random function constructed based on the {0,1}-NTRU problem is also resistant to quantum attacks.

[0063] Convert the pseudo-random function value v into a matrix, data service platform P s Assume the initial matrix D = 1 m×w , where D is an m×w matrix with each component equal to 1, and D i [v[i]]=0, that is, change the v[i]th element of the i-th row to 0, thus obtaining a new matrix D∈{0,1} m×w .

[0064] The step three is specifically as follows:

[0065] Step 3.1, Data Service Platform P s Execution: Data Service Platform P s Sending bits s[1],...,s[w]∈{0,1}, user P u The column vector {r i (0) ,r i (1)} i∈[w] , data service platform P s The column vector {r i} i∈[w] , where r i (0) +r i (1) =1 m ,r i =r i s[i] ∈{0,1} m ;

[0066] Step 3.2, User P u Execution: User P u The column vector {r i (0) ,r i (1)} i∈[w] And combined into a matrix And calculate the matrix and column vector i∈[w] and the column vector Δ i Send to P s ;

[0067] Step 3.3, Data Service Platform P s Execution: Data Service Platform P s Receive the column vector Δ sent in step 3.2 i Then calculate C, that is: when s[i] = 0, then C i =r i ;otherwise Output hash function value Here, s[i] represents the i-th bit of s.

[0068] The step 4 is specifically as follows:

[0069] Data Service Platform s Pack the hash function value h and construct a wrapper function:

[0070] ψ(h)=ψ(x)=ψ1(h)+ψ2(h),

[0071] Wherein, ψ1(h)=0, ψ2(h)=message, message is the message corresponding to the pseudo-random function value h;

[0072] Then use indistinguishable obfuscation to obfuscate the encapsulated function and get the obfuscated function And the obfuscation function Send to user P u .

[0073] The step five is specifically as follows:

[0074] User P u Encrypt the content y to be retrieved using a pseudo-random function to obtain a pseudo-random function value v:

[0075]

[0076] User P u Assume the initial matrix E∈1 m×w , where each component of the m×w matrix is ​​1, and let E i [v[i]]=0, that is, change the u[i]th element in the i-th row to 0, thus obtaining a new E∈{0,1} m×w , user P u Calculate the hash function value l associated with y, that is v1‖v2=(v1,v2);

[0077] User P u Confusion Function Enter search data The corresponding hash function value When user P u Retrieval data When , the confusion function The output is empty, which means the search failed. u Retrieval data When , the confusion function The output is the hash function value The corresponding message is displayed, indicating that the retrieval is successful.

[0078] A system for constructing a privacy information retrieval protocol based on an oblivious pseudo-random function, comprising:

[0079] System initialization module, system initialization, setting security parameters m, w, and hash functions and Step 1 of a construction method for implementing a privacy information retrieval protocol based on an oblivious pseudo-random function;

[0080] The oblivious transmission preparation module is based on the security parameters m,w, and hash functions and Performing oblivious pseudo-random function encryption to obtain a matrix D, which is used to implement step 2 of a construction method of a privacy information retrieval protocol based on an oblivious pseudo-random function;

[0081] The random pseudo-random function encryption module is based on the security parameters m,w, Hash functions and and matrix D are obliviously transmitted to obtain a hash function value h, which is used to implement step 3 of a construction method of a privacy information retrieval protocol based on an oblivious pseudo-random function;

[0082] Data packaging module, data service platform P s Pack the hash function value h into data, construct the encapsulation function, and then use indistinguishable obfuscation to confuse the encapsulation function to obtain the obfuscated function Step 4 of the construction method for implementing a privacy information retrieval protocol based on an oblivious pseudo-random function;

[0083] The user retrieval module uses a pseudo-random function to calculate the retrieval data and inputs it into the obfuscation function The retrieval is performed in order to hide the retrieval information, which is used to implement step five of a construction method of a privacy information retrieval protocol based on an inadvertent pseudo-random function.

[0084] A device for constructing a privacy information retrieval protocol based on an oblivious pseudo-random function, comprising:

[0085] Memory: used for storing a computer program for implementing a construction method of a privacy information retrieval protocol based on an oblivious pseudo-random function;

[0086] Processor: used to implement a construction method of a privacy information retrieval protocol based on an inadvertent pseudo-random function when executing the computer program.

[0087] The present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of a method for constructing a privacy information retrieval protocol based on an inadvertent pseudo-random function.

[0088] Simulation comparison:

[0089] Compared with the results of Chase et al. in the technical background, the simulation device is MacBookAir, Apple M1 chip, 8.00GB RAM, and the execution language is Python 3.12. The comparison results are as follows Figure 3 Simulation comparison chart of the present invention, where "Ours" represents the present invention, "CM20" represents the work of Chase et al., the horizontal axis "n" represents the number of hash function values ​​packaged by the data service platform, and the vertical axis "CPU Time" represents the time in milliseconds.

[0090] See also Figure 3 When n<125 milliseconds, the efficiency of the present invention is not as good as the results of Chase et al.; but when n>125 milliseconds, the efficiency of the present invention is better than the results of Chase et al., and as n increases, the efficiency difference between the two becomes more obvious.

Claims

1. A method for constructing a privacy information retrieval protocol based on a pseudo-random function, characterized in that: The steps include: Step 1: System initialization, setting security parameters m, w, l and hash function and Step 2: Based on the security parameters m, w, l and hash function set in step 1 and Perform random pseudo-random function encryption to obtain matrix D; Step 3: Based on the security parameters m, w, l and hash function set in step 1 and The matrix D obtained in step 2 is inadvertently transferred to obtain the hash function value h; Step 4: Data Service Platform P s Package the hash function value h obtained in step 3, construct the encapsulation function, and then use indistinguishable obfuscation to confuse the encapsulation function to obtain the obfuscated function Step 5: Use a pseudo-random function to calculate the retrieved data and input it into the obfuscation function obtained in step 4. The search is performed in the search, thereby hiding the search information.

2. According to claim 1, a method for constructing a privacy information retrieval protocol based on a pseudo-random function is characterized in that: The step 1 is specifically as follows: Set the security parameters of the protocol Represents a set of integers and sets three hash functions and in, Represents a univariate polynomial ring 3. The method for constructing a fast post-quantum private information retrieval protocol based on an oblivious pseudo-random function according to claim 1, characterized in that: The step 2 is specifically as follows: Data Service Platform s Select the pseudo-random function key Send the pseudo-random function key k to user P u , data service platform P s Input private data to the pseudo-random function Calculate the pseudorandom function value v: Where F represents a pseudo-random function, is the function for hashing the private data x, is a pseudo-random function based on the key k, For a pseudo-random function The hash function is processed twice and once by a pseudo-random function. u The obtained pseudo-random function value v is a result with privacy protection characteristics. The pseudo-random function value v combines the privacy data with the characteristics of the pseudo-random function. Convert the pseudo-random function value v into a matrix, data service platform P s Assume the initial matrix D = 1 m×w , where D is an m×w matrix with each component equal to 1, and D i [v[i]]=0, that is, change the v[i]th element of the i-th row to 0, thus obtaining a new matrix D∈{0,1} m×w .

4. The method for constructing a fast post-quantum private information retrieval protocol based on an oblivious pseudo-random function according to claim 1, characterized in that: The step three is specifically as follows: Step 3.1, Data Service Platform P s Execution: Data Service Platform P s Sending bits s[1],...,s[w]∈{0,1}, user P u Oblivious protocol to obtain the column vector associated with bits s[1],...,s[w] Data Service Platform s The column vector {r i } i∈[w] , where r i (0) +r i (1) =1 m ,r i =r i s[i] ∈{0,1} m ; Step 3.2, User P u Execution: User P u The column vector {r i (0) ,r i (1) } i∈[w] And combined into a matrix And calculate the matrix and column vector i∈[w] and the column vector Δ i Send to P s ; Step 3.3, Data Service Platform P s Execution: Data Service Platform P s Receive the column vector Δ sent in step 3.2 i Then calculate C, that is: when s[i] = 0, then C i =r i ;otherwise Output hash function value Here, s[i] represents the i-th bit of s.

5. The method for constructing a fast post-quantum private information retrieval protocol based on an oblivious pseudo-random function according to claim 1, characterized in that: The step 4 is specifically as follows: Data Service Platform s Pack the hash function value h and construct a wrapper function: ψ(h)=ψ(x)=ψ1(h)+ψ2(h), Wherein, ψ1(h)=0, ψ2(h)=message, message is the message corresponding to the pseudo-random function value h; Then use indistinguishable obfuscation to obfuscate the encapsulated function and get the obfuscated function And the obfuscation function Send to user P u .

6. The method for constructing a privacy information retrieval protocol based on an oblivious pseudo-random function according to claim 1, characterized in that: The step five is specifically as follows: User P u Encrypt the content y to be retrieved using a pseudo-random function to obtain a pseudo-random function value v: User P u Assume the initial matrix E∈1 m×w , where each component of the m×w matrix is ​​1, and let E i [v[i]]=0, that is, change the u[i]th element in the i-th row to 0, thus obtaining a new E∈{0,1} m×w , user P u Calculate the hash function value l associated with y, that is User P u Confusion Function Enter search data The corresponding hash function value When user P u Retrieval data When , the confusion function The output is empty, which means the search failed. u Retrieval data When , the confusion function iO(ψ,l ui ) output is the hash function value l ui The corresponding message is displayed, indicating that the retrieval is successful.

7. A system for constructing a privacy information retrieval protocol based on an oblivious pseudo-random function based on the method of any one of claims 1 to 6, characterized in that: include: System initialization module, system initialization, setting security parameters m, w, l and hash function and Oblivious transfer preparation module based on security parameters m,w,l and hash function and Perform random pseudo-random function encryption to obtain matrix D; Oblivious pseudo-random function encryption module, based on security parameters m, w, l, hash function and And matrix D is obliviously transferred to obtain the hash function value h; Data packaging module, data service platform P s Pack the hash function value h into data, construct the encapsulation function, and then use indistinguishable obfuscation to confuse the encapsulation function to obtain the obfuscation function iO(ψ,·); The user retrieval module uses a pseudo-random function to calculate the retrieval data and inputs it into the obfuscation function iO(ψ,·) for retrieval, thereby realizing the hiding of the retrieval information.

8. A device for constructing a privacy information retrieval protocol based on an oblivious pseudo-random function, characterized in that: include: Memory: used for storing a computer program for implementing a method for constructing a privacy information retrieval protocol based on an inadvertent pseudo-random function as claimed in any one of claims 1 to 6; Processor: used to implement the construction method of a privacy information retrieval protocol based on an inadvertent pseudo-random function as described in any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for constructing a privacy information retrieval protocol based on an inadvertent pseudo-random function as described in any one of claims 1 to 6 are implemented.

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