Anti-quantum encrypted multi-valued query method and device

Abstract

The invention provides an anti-quantum encrypted multi-valued query method and device.The method comprises the steps that a query request sent by a client side for a target keyword is obtained, and the query request is a request generated by the client side by encrypting the target keyword through an anti-quantum pseudo-random function of a server side according to a secret key of the server side; according to the query request, querying a target encrypted multi-valued mapping table to obtain an encrypted multi-valued query result set, the target encrypted multi-valued mapping table being an encrypted multi-valued mapping table generated by encrypting an anti-quantum public key and a multi-valued mapping table of the client in advance, and returning the encrypted multi-valued query result set to the client, and sending the encrypted multi-valued query result set to the client, so that the client decrypts the encrypted multi-valued query result set to obtain a decryption result, and determining whether the target keyword is tampered or not. The quantum computing attack is resisted by using the anti-quantum characteristic, and the leakage of the query mode is avoided by encrypting the request format, so that the client dynamically supervises the behavior of the server by decrypting the result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cryptographic application, in particular to an anti-quantum encrypted multi-value query method and device. BACKGROUND

[0002] In today's digital age, secure storage and efficient retrieval of data have become a crucial issue. As an emerging cryptography technology, structured encryption (STE) has emerged to meet this challenge. STE allows data owners to outsource encrypted structured data to untrusted servers while still being able to perform specific operations on these data, such as search and query, without exposing sensitive content of the data. Encrypted multi-map (EMM), as an important special case of STE, focuses on encrypted storage of key-value pair sets and supports efficient query operations based on keys, and is widely used in the design of symmetric searchable encryption (SSE) schemes with optimal search complexity, range queries in encrypted databases, and SQL query processing in many fields. The core goal of EMM is to achieve encrypted storage and query of multi-value mapping data structure under the premise of protecting data privacy, ensuring that the server cannot obtain sensitive information about data content and query patterns when processing encrypted data, except for the pre-defined acceptable leakage information.

[0003] At present, academia and industry have carried out extensive research on EMM and proposed various EMM schemes based on symmetric encryption. These schemes balance the relationship between data privacy protection and query efficiency to some extent, but still have obvious limitations. First, they are all based on symmetric encryption mechanism, requiring both parties to share the same key, which may cause security risks in the key management and distribution process, especially in complex scenarios involving a large number of users or cross-domain communication, where key synchronization update and secure storage face great challenges. Secondly, and more importantly, existing research has almost not touched on EMM schemes under the public key encryption system. Public key encryption, with its asymmetric advantage, can effectively solve the difficulties of symmetric encryption in key management, but has rarely been applied and explored in the field of EMM. In addition, although quantum computing technology is not yet mature, its potential threat cannot be ignored. Once quantum computers are put into practical use, EMM schemes based on symmetric encryption may face the risk of significantly reduced security strength due to the powerful computing power of quantum computers. Symmetric encryption algorithms usually rely on mathematical problems such as large integer factorization and discrete logarithm, while quantum computers can use quantum algorithms such as Shor to break these problems in polynomial time, thus easily decrypting encrypted data and obtaining sensitive information. SUMMARY

[0004] The present application aims at the deficiencies in the prior art, and provides an anti-quantum encrypted multi-value query method and device, so as to receive an encrypted query request generated by a client based on an anti-quantum pseudo-random function, perform query and return a result in combination with a preset target encrypted multi-value mapping table, resist quantum computing attacks by using anti-quantum characteristics, avoid query mode leakage by using an encrypted request format, and provide a basis for subsequent integrity verification of the client, so that the client realizes dynamic supervision on the behavior of the server by decrypting the result.

[0005] To achieve the above object, the technical scheme adopted by the embodiments of the present application is as follows: In a first aspect, the embodiments of the present application provide an anti-quantum encrypted multi-value query method applied to a server, which comprises the following steps: Obtaining a query request for a target keyword sent by a client; the query request is a request generated by encrypting the target keyword by the client based on a secret key of the server and using an anti-quantum pseudo-random function of the server; According to the query request, querying a target encrypted multi-value mapping table to obtain an encrypted multi-value query result set; the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated by encrypting an anti-quantum public key of the client and the multi-value mapping table in advance; Returning the encrypted multi-value query result set to the client, so that the client decrypts the encrypted multi-value query result set to obtain a decrypted result and determines whether the target keyword is tampered with.

[0006] In an optional implementation, before obtaining the query request for the target keyword sent by the client, the method further comprises the following steps: Encrypting the values of each key in the multi-value mapping table to generate an initial encrypted multi-value mapping table according to the anti-quantum public key of the client and using an anti-quantum public key encryption algorithm; Encrypting each ciphertext in the initial encrypted multi-value mapping table to generate a pseudo-random encrypted multi-value mapping table according to the secret key of the server and using the anti-quantum pseudo-random function of the server; Generating the target encrypted multi-value mapping table according to the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table.

[0007] In an optional implementation, encrypting the values of each key in the multi-value mapping table to generate an initial encrypted multi-value mapping table according to the anti-quantum public key of the client and using an anti-quantum public key encryption algorithm comprises the following steps: Mapping each key-value pair in the multi-value mapping table to a preset integer space to obtain a hash table by using a hash function; After filtering each index in the hash table, target indexes that meet preset conditions are obtained; Push the element at the target index in the hash table onto the stack to obtain the XOR filter stack; Based on the quantum-resistant public key, the quantum-resistant public key encryption algorithm is used to encrypt each element in the XOR filter stack to generate the initial encrypted multi-value mapping table.

[0008] In an optional implementation, generating a target encrypted multi-value mapping table based on the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table includes: Perform an XOR operation on the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table; The target encrypted multi-value mapping table is obtained by randomly filling the encrypted multi-value mapping table after the XOR operation.

[0009] In an optional implementation, the step of querying the target encrypted multi-value mapping table according to the query request to obtain an encrypted multi-value query result set includes: Based on the query request, obtain the corresponding quantum-resistant pseudo-random tag; Based on the anti-quantum pseudo-random label, each ciphertext in the target encrypted multi-value mapping table is matched to obtain the target ciphertext corresponding to the anti-quantum pseudo-random label, and the set of encrypted multi-value query results containing the target ciphertext is determined.

[0010] Secondly, embodiments of this application also provide a quantum-resistant encrypted multi-value query method, applied to a client, the method comprising: Obtain the server's secret key; Based on the server's secret key, the target keyword is encrypted using the server's quantum-resistant pseudo-random function to generate a query request; The query request is sent to the server so that the server queries the target encrypted multi-value mapping table according to the query request and obtains an encrypted multi-value query result set; wherein, the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated by the server in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table. Receive the encrypted multi-value query result set returned by the server; The encrypted multi-value query result set is decrypted to obtain the decryption result, and it is determined whether the target keyword has been tampered with.

[0011] In an optional implementation, the step of receiving the encrypted multi-value query result set, decrypting the encrypted multi-value query result set to obtain a decryption result, and determining whether the target keyword has been tampered with further includes: Based on the client's quantum-resistant private key, the encrypted multi-value query result set is decrypted using a quantum-resistant private key decryption algorithm to obtain the decryption result; If the decryption result matches the location of the target keyword, then it is determined that the target keyword has not been tampered with; If the decryption result does not match the position of the target keyword, then the target keyword is determined to have been tampered with.

[0012] In an optional implementation, the method further includes: If it is determined that the target keyword has been tampered with, the query request is sent to the server again, so that the server queries the target encrypted multi-value mapping table again according to the query request to obtain a new encrypted multi-value query result set.

[0013] Thirdly, embodiments of this application also provide a quantum-resistant encrypted multi-value query device, applied to a server, the device comprising: The first acquisition module is used to acquire a query request for a target keyword sent by the client; the query request is a request generated by the client encrypting the target keyword using the server's secret key and the server's anti-quantum pseudo-random function. The query module is used to query the target encrypted multi-value mapping table according to the query request and obtain an encrypted multi-value query result set; the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table. The return module is used to return the encrypted multi-value query result set to the client, so that the client can decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with.

[0014] Fourthly, embodiments of this application also provide a quantum-resistant encrypted multi-value query device, applied to a client, the device comprising: The second acquisition module is used to acquire the server's secret key; The second generation module is used to encrypt the target keyword using the server's secret key and the server's quantum-resistant pseudo-random function to generate a query request; The sending module is used to send the query request to the server, so that the server queries the target encrypted multi-value mapping table according to the query request and obtains an encrypted multi-value query result set; wherein, the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated by the server in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table; A receiving module is used to receive the encrypted multi-value query result set returned by the server; The decryption module is used to decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with.

[0015] The beneficial effects of this application are: This application provides a quantum-resistant encrypted multi-value query method and apparatus applied to a server. The method includes: acquiring a query request sent by a client for a target keyword, wherein the query request is a request generated by the client encrypting the target keyword using the server's secret key and a quantum-resistant pseudo-random function; querying a target encrypted multi-value mapping table according to the query request to obtain an encrypted multi-value query result set, wherein the target encrypted multi-value mapping table is an encrypted multi-value mapping table pre-generated by encrypting the client's quantum-resistant public key and the multi-value mapping table; returning the encrypted multi-value query result set to the client so that the client can decrypt the encrypted multi-value query result set to obtain a decryption result and determine whether the target keyword has been tampered with.

[0016] The method of this application receives encrypted query requests generated by the client based on a quantum-resistant pseudo-random function, executes the query and returns the results by combining the pre-set target encrypted multi-value mapping table, utilizes quantum-resistant properties to resist quantum computing attacks, avoids query pattern leakage through encrypted request format, and provides a basis for subsequent integrity verification by the client. This allows the client to dynamically supervise the behavior of the server by decrypting the results, ensuring the integrity and credibility of the data retrieval process, and realizing secure and efficient retrieval of encrypted data in a quantum environment. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 One of the flowcharts for a quantum-resistant encrypted multi-value query method provided in this application embodiment; Figure 2 A second schematic flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment; Figure 3 A third schematic flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment; Figure 4A fourth flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment; Figure 5 Fifth flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment; Figure 6 A flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment is shown in Figure 6. Figure 7 The seventh flowchart illustrates a quantum-resistant encrypted multi-value query method provided in this application embodiment; Figure 8 A schematic diagram of the functional modules of a quantum-resistant encrypted multi-value query device provided in an embodiment of this application; Figure 9 A schematic diagram of the functional modules of another quantum-resistant encrypted multi-value query device provided in an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0020] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] In the description of this application, it should be noted that if the terms "upper", "lower", etc. appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] Furthermore, the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Additionally, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0024] This application proposes a quantum-resistant encrypted multi-valued query method. This method replaces traditional symmetric encryption algorithms with quantum-resistant public-key encryption algorithms, fundamentally improving the encryption system's ability to withstand future quantum computing attacks. Simultaneously, by designing a mechanism for the client to record the corresponding positions of keywords, the integrity of the server's returned results is verified after the query, effectively avoiding the storage space waste caused by generating additional verification data structures and significantly improving storage efficiency. The method provided in this application not only theoretically expands the research scope of Encrypted Multi-Maps (EMMs) and fills the research gap in the field of public-key quantum-resistant encryption, but also provides a more forward-looking and practical technical path for data privacy protection and efficient retrieval in practical applications. This establishes a solid data security barrier before the advent of the quantum computing era, ensuring the security and privacy of various sensitive information in complex network environments.

[0025] Encrypted Multiple Value Mapping (EMM) is a structured encryption technique that protects data privacy. It securely stores collections of key-value pairs, where one key corresponds to multiple values, and allows clients to retrieve data via encrypted queries. Its core challenge is hiding the response length, i.e., the actual number of values; otherwise, attackers could exploit this information to launch leak and abuse attacks. Structured Encryption (STE) is a technique used to encrypt data while preserving its structural information, enabling specific operations such as searching and querying.

[0026] Furthermore, the quantum-resistant encrypted multi-value query method provided in this application involves two core roles: a client and a server. The client is responsible for key generation, metadata management, and integrity verification, while the server undertakes data structure obfuscation construction and encryption operations. The following detailed explanation, in conjunction with the accompanying drawings and specific examples, illustrates the quantum-resistant encrypted multi-value query method provided in this application, applied to the server side. Figure 1 This application provides a schematic flowchart of one of the quantum-resistant encrypted multi-value query methods; as shown below. Figure 1 As shown, the method includes: S101. Obtain the query request sent by the client for the target keyword.

[0027] The query request is generated by the client using the server's secret key and the server's quantum-resistant pseudo-random function to encrypt the target keyword.

[0028] In this embodiment, the client obtains the secret key published by the server and uses the server's quantum-resistant pseudo-random function to encrypt the target keyword and generate a query request.

[0029] Specifically, the client performs restricted pseudo-random function calculations based on the target keywords of the query. and secret key Calculate pseudo-random labels In other words, query request, pseudo-random label Represented as: , This is represented as a quantum-resistant pseudo-random function on the server side. The query request contains encrypted index information of the target keyword and only supports restricted operations performed on the server side.

[0030] Among them, the obtained pseudo-random labels Allow variables Perform the following restricted pseudo-random operations:

[0031] The algorithm for executing the pseudo-random function is given, with pseudo-random labels as input. and variables Output the calculation result; only when the variable With the target keywords of the query Related ( )hour, Only then will a valid result be returned. If the variable With the target keywords of the query Irrelevant ( ), Returns an invalid result directly. The server is unable to perform subsequent calculations, thus restricting the server to accessing only the current target keyword. The corresponding encrypted data.

[0032] S102. Based on the query request, query the target encrypted multi-value mapping table to obtain the encrypted multi-value query result set.

[0033] The target encrypted multi-value mapping table is an encrypted multi-value mapping table generated in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table.

[0034] Specifically, the server pre-encrypts the multi-value mapping table based on the client's quantum-resistant public key to generate the target encrypted multi-value mapping table. The multi-value mapping table includes multiple key-value pairs, i.e. multiple sets of data. By encrypting the multi-value mapping table, a quantum-resistant, leakage-proof, and tamper-proof target encrypted multi-value mapping table (EMM) is generated.

[0035] Then the server responds to the query request. Search the target encrypted multi-valued mapping table for the set of encrypted multi-valued query results corresponding to the target keyword.

[0036] S103. Return the encrypted multi-value query result set to the client so that the client can decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with.

[0037] Specifically, the server returns the encrypted multi-value query result set to the client, so that the client can decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with based on the decryption result.

[0038] In summary, this application provides a quantum-resistant encrypted multi-value query method applied to a server. The method includes: acquiring a query request from a client targeting a target keyword; the query request being a request generated by the client encrypting the target keyword using the server's secret key and a quantum-resistant pseudo-random function; querying a target encrypted multi-value mapping table based on the query request to obtain an encrypted multi-value query result set; the target encrypted multi-value mapping table being an encrypted multi-value mapping table pre-generated by encrypting the client's quantum-resistant public key and the multi-value mapping table; and returning the encrypted multi-value query result set to the client, enabling the client to decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with.

[0039] The method of this application receives encrypted query requests generated by the client based on a quantum-resistant pseudo-random function, executes the query and returns the results by combining the pre-set target encrypted multi-value mapping table, utilizes quantum-resistant properties to resist quantum computing attacks, avoids query pattern leakage through encrypted request format, and provides a basis for subsequent integrity verification by the client. This allows the client to dynamically supervise the behavior of the server by decrypting the results, ensuring the integrity and credibility of the data retrieval process, and realizing secure and efficient retrieval of encrypted data in a quantum environment.

[0040] Based on the quantum-resistant encrypted multi-valued query method provided in the above embodiments, this application also provides another possible implementation of the quantum-resistant encrypted multi-valued query method. Figure 2 This is a second flowchart illustrating a quantum-resistant encrypted multi-value query method provided in an embodiment of this application, as shown below. Figure 2 As shown, before obtaining the query request sent by the client for the target keyword, the method further includes: S201. Based on the client's quantum-resistant public key, use a quantum-resistant public key encryption algorithm to encrypt the values ​​of each key in the multi-value mapping table to generate an initial encrypted multi-value mapping table.

[0041] In this embodiment, the client pre-executes .KeyGen( Generating quantum-resistant keys Keep the private key . It is a quantum-resistant public-key cryptographic triplet, comprising three algorithms: KeyGen (key generation algorithm), PublicEnc (public key encryption algorithm), and PublicDec (private key encryption algorithm). Specifically, the client generates the quantum-resistant key as follows: First, it generates the core parameters of the lattice cryptosystem, including the security dimension, modulus, and error distribution. Then, based on the learning with errors (LWE) problem, it randomly selects a short integer vector as the quantum-resistant private key. Simultaneously, it calculates the corresponding quantum-resistant public key, which is composed of the product of a uniformly randomly sampled matrix and the quantum-resistant private key, superimposed with a specific error vector. Finally, it outputs a quantum-resistant public-private key pair that satisfies quantum security. This process ensures that the quantum-resistant private key is securely stored by the client, while the quantum-resistant public key can be publicly distributed.

[0042] Among them, the fault-tolerant learning problem (LWE) is a modern cryptography concept, and its core idea is: given a random matrix... and a vector ,in It is a secret vector. It is a small error vector that typically follows a discrete Gaussian distribution, i.e., an error distribution. It is a large prime number, i.e., the modulus. Modular operation is used to solve for the secret vector. It is computationally infeasible. The security of this problem is based on lattice problems that are difficult for quantum computers to solve efficiently, making it the theoretical cornerstone for building quantum-resistant encryption algorithms (such as public-key encryption and pseudo-random functions).

[0043] The server obtains the quantum-resistant public key from the client and uses a quantum-resistant public key encryption algorithm to encrypt the value of each key in the multi-value mapping table, generating an initial encrypted multi-value mapping table.

[0044] Figure 3 This is the third flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment. Figure 3 As shown, step S201 specifically includes: S301. Using a hash function, each key-value pair in the multi-value mapping table is mapped to a preset integer space to obtain a hash table.

[0045] S302. After filtering each index in the hash table, the target index that meets the preset conditions is obtained.

[0046] S303. Push the element at the target index in the hash table onto the stack to obtain the XOR filter stack.

[0047] Specifically, the pseudocode representation of processing multi-valued mapping tables and generating an XOR filter stack is as follows: while( x ∈MM){ for( t =0; t < r ; t ++){ T [ ]= x ; / / It maps strings of arbitrary length to Hash functions for integers; } } for( i =0; i < s ; i ++){ if| T [ i ]=1|{ Add i to the queue; } } while(Queue≠null){ / / null represents an empty set} Elements in a Queuei Depart; make x = T [ i ]; ( x , i Push onto the stack; for( t =0; t < r ; t ++){ T [ ]= T [ ]\{x}; if| T [ i ]=1|{ Will Join the queue; } } } if |Stack|≠| S |{ Termination of process; } Return to Stack.

[0048] The multi-valued mapping table is represented as follows: The server generates an XOR filter stack `Stack = MappingStep(MM)`. It randomly selects large integers `r` and `s` (where `r` is much larger than `s`), initializes the XOR filter stack `Stack`, queue `Queue`, and hash table `T`, and sets them to empty. Then, it uses a hash function to map any string (i.e., each key-value pair in the multi-value mapping table) to a preset integer space. The system dynamically filters indexes that meet preset conditions and stores them in a queue. The preset condition is T[i]=1, which is a single data index. Then, through iterative operations, the elements of the target index in the hash table are pushed into the stack in an orderly manner, and finally an XOR filter stack Stack that matches the size of the original dataset is formed.

[0049] S304. Based on the quantum-resistant public key, use the quantum-resistant public key encryption algorithm to encrypt each element in the XOR filter stack to generate an initial encrypted multi-value mapping table.

[0050] Specifically, execution .PublicEnc( The algorithm generates ciphertext and writes it into EMM[i], where PublicEnc is a quantum-resistant public-key encryption algorithm. For the client's quantum-resistant public key, Then, based on the quantum-resistant public key, the quantum-resistant public key encryption algorithm is used to encrypt each element in the XOR filter stack, generating the initial encrypted multi-value mapping table EMM[i].

[0051] S202. Based on the server's secret key, use the server's quantum-resistant pseudo-random function to encrypt each ciphertext in the initial encrypted multi-value mapping table to generate a pseudo-random encrypted multi-value mapping table.

[0052] S203. Generate the target encrypted multi-value mapping table based on the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table.

[0053] Figure 4 This is the fourth flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment. Figure 4 As shown, S203 specifically includes: S401. Perform an XOR operation on the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table.

[0054] S402. Randomly fill the encrypted multi-value mapping table after the XOR operation to obtain the target encrypted multi-value mapping table.

[0055] Specifically, the pseudocode representation of generating the target encrypted multi-value mapping table is as follows: while { implement .PublicEnc( The algorithm generates ciphertext and writes it to EMM[i]. for(t=0;t<3;t++){ if( ){ if(EMM[ ]=null){ / / It is a keyed quantum-resistant pseudo-random function Fill EMM with random strings of 0s and 1s. ]; } EMM[i] = EMM[i] EMM ]; } } } while( ){ if EMM[j] = null{ Fill EMM[j] with random strings of 0s and 1s; } } Return EMM.

[0056] Specifically, during the construction phase of the target encrypted multi-valued map, the server uses a quantum-resistant public-key encryption algorithm to process the data: the plaintext values ​​to be encrypted, i.e., the values ​​of each key in the multi-valued map table, are binary encoded and mapped to a lattice space, and the encryption operation is performed using the receiver's quantum-resistant public key. Specifically, the plaintext is embedded into a linear system constructed from the quantum-resistant public-key matrix, and a small error conforming to a Gaussian distribution is injected, ultimately generating the ciphertexts in the initial encrypted multi-valued map table. This ciphertext is essentially an LWE instance, and its security relies on the computational complexity of the lattice problem, effectively resisting quantum computing attacks.

[0057] The quantum-resistant pseudo-random function F is a quantum-resistant pseudo-random function with a secret key. The input is key||c||t (t=0,1,2, a total of 3 associated positions), and the output is the index. If the EMM position corresponding to the index generated by the pseudo-random function is empty, it is first filled with random 0 and 1 strings to obtain a pseudo-random encrypted multi-value mapping table.

[0058] The initial encrypted multi-value mapping table EMM[i] is XORed with the contents of the pseudo-random encrypted multi-value mapping table to obtain the XORed encrypted multi-value mapping table. The purpose of XOR obfuscation is that even if an attacker obtains EMM, they cannot directly deduce the original data from the ciphertext, because EMM[i] is the contents of the initial encrypted multi-value mapping table XORed with the contents of the pseudo-random encrypted multi-value mapping table. Only by knowing the secret key of the pseudo-random function can the ciphertext of the initial encrypted multi-value mapping table be calculated in reverse.

[0059] Finally, the encrypted multi-value mapping table after the XOR operation is randomly filled to obtain the target encrypted multi-value mapping table, ensuring that there are no empty values ​​in the EMM. Empty values ​​will reveal the information that there is no valid data at that position, and attackers may infer the data pattern through the distribution of empty values. After filling with random 0 and 1 strings, each position of the EMM looks like valid ciphertext, enhancing confidentiality.

[0060] The method provided in this application first transforms the original multi-valued mapping table into an ordered and secure initial encryption table through a series of operations including segmented hash mapping, index filtering, stack structure construction, and quantum-resistant encryption. This achieves structured obfuscation of the data, reducing the risk of attackers inferring data associations, and lays a quantum-resistant security foundation based on lattice cryptography. It also provides ordered and traceable data structure support for subsequent secondary encryption. Then, a quantum-resistant pseudo-random function is used to perform secondary obfuscation. Finally, the ciphertext information of the initial encryption table and the pseudo-random encryption table is fused through XOR operation, and empty indexes are randomly filled. This solves the key management problem of traditional symmetric encryption, enhances data privacy protection through multi-layer obfuscation, avoids data distribution leakage due to empty indexes, and ensures the security and structural integrity of encrypted storage.

[0061] This application also provides another possible implementation of a quantum-resistant encrypted multi-value query method. Figure 5 This is the fifth flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment. Figure 5 As shown, based on the query request, the target encrypted multi-value mapping table is queried to obtain a set of encrypted multi-value query results, including: S501. Based on the query request, obtain the corresponding quantum-resistant pseudo-random tag.

[0062] S502. Based on the anti-quantum pseudo-random label, match each ciphertext in the target encrypted multi-value mapping table to obtain the target ciphertext corresponding to the anti-quantum pseudo-random label, and determine the set of encrypted multi-value query results containing the target ciphertext.

[0063] In this embodiment, the server receives the query request from the client and obtains the corresponding quantum-resistant pseudo-random tag. Based on the quantum-resistant pseudo-random label, each ciphertext in the target encrypted multi-valued mapping table is matched to obtain the target ciphertext with the quantum-resistant pseudo-random label, and the set of encrypted multi-valued query results containing the target ciphertext is determined. Specifically, the pseudocode representation of determining the set of encrypted multi-valued query results containing the target ciphertext is as follows: for( k =0; k < l ; k ++){ for( t =0; t <3; t ++){ = ; =EMM[ ]; ; } } return .

[0064] Specifically, after receiving a query request, the server initializes an empty result set, the size of which is... l By traversing each ciphertext in the target encrypted multi-value mapping table and combining it with quantum-resistant pseudo-random labels to parse the associated data blocks layer by layer, an encrypted query result set is finally generated.

[0065] Where, from the outer loop k=0 to l-1: k is the multi-value shard index corresponding to the current target keyword key. Iterate through each shard to ensure each value can be retrieved. The inner loop t=0 to 2: t is the number of XOR obfuscation operations. The purpose is to reverse the XOR obfuscation process, which uses three pseudo-random indexes to obfuscate the ciphertext. Here, the same three XOR operations are needed to restore the original encrypted ciphertext. The server does not have the target keyword. It can only be invoked through the anti-quantum pseudo-random tag provided by the client. Calculate a pseudo-random index, and only obtain the index that matches the current target keyword. Relevant valid indexes. Extract pseudo-random indexes from the encrypted multi-valued mapping (EMM). Corresponding target ciphertext Then, perform an XOR aggregation with the initial empty result set to obtain the final encrypted multi-value query result containing the target ciphertext. Each element These are the original encrypted ciphertexts of the corresponding fragments. They have only been restored by XOR obfuscation without being decrypted, ensuring data security during transmission.

[0066] The method provided in this application embodiment locates the target ciphertext based on quantum-resistant pseudo-random tags and performs XOR aggregation to generate an encrypted query result set. This not only achieves accurate retrieval of encrypted data and avoids irrelevant data transmission occupying bandwidth, but also hides the real response length through ciphertext aggregation operation to resist leakage and abuse attacks. At the same time, it relies on quantum-resistant characteristics to ensure the security of the query process and adapts to the efficient data interaction needs of cross-domain collaboration scenarios.

[0067] This application also provides another possible implementation of a quantum-resistant encrypted multi-value query method, applied to a client-side application. Figure 6 This is the sixth flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment. Figure 6 As shown, the method includes: S601. Obtain the server's secret key.

[0068] S602. Based on the server's secret key, use the server's quantum-resistant pseudo-random function to encrypt the target keyword and generate a query request.

[0069] In this embodiment, the client obtains the server's pseudo-random function secret key in advance from the secure channel. The system also records the location of each keyword locally to check whether the server has tampered with the location after the query is completed.

[0070] The client then performs a restricted pseudo-random function calculation based on the target keywords of the query. and secret key Calculate pseudo-random labels In other words, query request, pseudo-random label Represented as: , This is represented as a quantum-resistant pseudo-random function on the server side. The query request contains encrypted index information of the target keyword and only supports restricted operations performed on the server side.

[0071] Among them, the obtained pseudo-random labels Allow variables Perform the following restricted pseudo-random operations:

[0072] The algorithm for executing the pseudo-random function is given, with pseudo-random labels as input. and variables Output the calculation result; only when the variable With the target keywords of the query Related ( )hour, Only then will a valid result be returned. If the variable With the target keywords of the query Irrelevant ( ), Returns an invalid result directly. The server is unable to perform subsequent calculations, thus restricting the server to accessing only the current target keyword. The corresponding encrypted data.

[0073] S603. Send a query request to the server so that the server can query the target encrypted multi-value mapping table according to the query request and obtain the encrypted multi-value query result set.

[0074] The target encrypted multi-value mapping table is an encrypted multi-value mapping table generated by the server in advance by encrypting the client's quantum-resistant public key and multi-value mapping table.

[0075] Specifically, a query request is sent to the server. The server queries the target encrypted multi-value mapping table according to the query request and obtains the encrypted multi-value query result set. The specific query process is explained in the above steps S101-S502, and will not be repeated here.

[0076] S604. Receive the encrypted multi-value query result set returned by the server.

[0077] S605. Decrypt the encrypted multi-value query result set to obtain the decryption result and determine whether the target keyword has been tampered with.

[0078] Specifically, the client receives the encrypted multi-value query result set sent by the server. Using quantum-resistant private keys Execute decryption algorithm .PublicDec( ),if .PublicDec( If the decryption result is not a terminator, the decryption result is recorded. The decryption result is automatically compared with the keyword location metadata pre-stored on the client to determine if the target keyword has been tampered with.

[0079] Optionally, if it is determined that the target keyword has been tampered with, a query request is sent to the server again, so that the server queries the target encrypted multi-value mapping table again according to the query request and obtains a new encrypted multi-value query result set.

[0080] After receiving a new set of encrypted multi-value query results, the client continues to decrypt the new set of encrypted multi-value query results to determine whether the target keyword has been tampered with.

[0081] In summary, this application provides a quantum-resistant encrypted multi-value query method applied to a client. The method includes: obtaining a server's secret key; encrypting a target keyword using the server's quantum-resistant pseudo-random function based on the server's secret key; generating a query request; sending the query request to the server, so that the server queries a target encrypted multi-value mapping table according to the query request to obtain an encrypted multi-value query result set. The target encrypted multi-value mapping table is an encrypted multi-value mapping table pre-generated by the server by encrypting the client's quantum-resistant public key and the multi-value mapping table; receiving the encrypted multi-value query result set returned by the server; decrypting the encrypted multi-value query result set to obtain a decryption result; and determining whether the target keyword has been tampered with.

[0082] By replacing traditional symmetric encryption with a quantum-resistant public-key algorithm, this solution addresses the challenges of key distribution and management in cross-domain scenarios. It utilizes pre-stored keyword location metadata on the client side and automatic comparison with decryption results to achieve tamper detection without additional data structure verification, significantly reducing storage overhead. A lattice-based encryption layer ensures the solution resists quantum attacks such as Shor's algorithm, providing long-term security. Simultaneously, the server-side employs multi-layered obfuscation structures and ciphertext operations using large integer parameters, supporting efficient multi-value association queries. Client-side query request generation and re-query mechanisms further guarantee the integrity and reliability of the query process. This solution provides an integrated solution for sensitive data in future quantum computing environments (such as encrypted databases and privacy-preserving retrieval systems), combining quantum-resistant security, low storage overhead, and efficient retrieval capabilities, laying a technological foundation for cross-domain data collaboration in high-security fields such as finance, healthcare, and government.

[0083] This application also provides another possible implementation of a quantum-resistant encrypted multi-value query method. Figure 7 This is the seventh flowchart illustrating a quantum-resistant encrypted multi-value query method provided in this application embodiment, as shown below. Figure 7 As shown, the function receives an encrypted multi-value query result set, decrypts the encrypted multi-value query result set to obtain the decryption result, and determines whether the target keyword has been tampered with. It also includes: S701. Based on the client's quantum-resistant private key, use the quantum-resistant private key decryption algorithm to decrypt the encrypted multi-value query result set to obtain the decryption result.

[0084] S702. If the decryption result matches the location of the target keyword, then it is determined that the target keyword has not been tampered with.

[0085] S703. If the decryption result does not match the position of the target keyword, then the target keyword has been tampered with.

[0086] In this embodiment, the client pre-executes .KeyGen( Generating quantum-resistant keys Keep the private key . It is a quantum-resistant public-key cryptographic triplet, comprising three algorithms: KeyGen (key generation algorithm), PublicEnc (public key encryption algorithm), and PublicDec (private key encryption algorithm). Specifically, the client generates the quantum-resistant key as follows: First, it generates the core parameters of the lattice cryptosystem, including the security dimension, modulus, and error distribution. Then, based on the learning with errors (LWE) problem, it randomly selects a short integer vector as the quantum-resistant private key. Simultaneously, it calculates the corresponding quantum-resistant public key, which is composed of the product of a uniformly randomly sampled matrix and the quantum-resistant private key, superimposed with a specific error vector. Finally, it outputs a quantum-resistant public-private key pair that satisfies quantum security. This process ensures that the quantum-resistant private key is securely stored by the client, while the quantum-resistant public key can be publicly distributed.

[0087] The client then receives the encrypted multi-value query result set sent by the server. Then, use a quantum-resistant private key. Execute decryption algorithm .PublicDec( ),if .PublicDec( If the decryption result is not a terminator, the decryption result is recorded. The quantum-resistant decryption algorithm works as follows: The quantum-resistant private key is used to perform an inner product operation with the ciphertext. The short vector characteristic of the quantum-resistant private key eliminates noise interference introduced during encryption, restoring an approximate value containing the plaintext. Then, modular operations are used to remove redundant information, recovering the original plaintext binary sequence. If the decryption result matches the locally recorded keyword position metadata, the target keyword is determined not to have been tampered with. If the decryption result does not match the locally recorded keyword position metadata, the target keyword is determined to have been tampered with, and the server-side returned result is considered abnormal.

[0088] The method provided in this application uses a quantum-resistant private key to decrypt the query results and performs matching and verification through locally pre-stored keyword location metadata. This achieves secure decryption of the encrypted results, resists quantum computing cracking by relying on lattice cryptography characteristics, and completes tamper detection without additional data structure verification, reducing storage overhead. At the same time, the re-query mechanism ensures data integrity and provides reliable protection for the use of sensitive data.

[0089] The following continues to explain the quantum-resistant encrypted multi-value query device provided in any of the above embodiments of this application. Its specific implementation process and the resulting technical effects are the same as those in the corresponding method embodiments. For the sake of brevity, parts not mentioned in this embodiment can be referred to the corresponding content in the method embodiments.

[0090] Figure 8 This is a functional module diagram of a quantum-resistant encrypted multi-value query device provided in an embodiment of this application. It is applied to a server, such as... Figure 8 As shown, the quantum-resistant encrypted multi-value query device 100 includes: The first acquisition module 110 is used to acquire the query request sent by the client for the target keyword; the query request is a request generated by the client using the server's secret key and the server's anti-quantum pseudo-random function to encrypt the target keyword. The query module 120 is used to query the target encrypted multi-value mapping table according to the query request and obtain the encrypted multi-value query result set; the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table; The return module 130 is used to return an encrypted multi-value query result set to the client, so that the client can decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with.

[0091] Optionally, the device further includes: The first generation module is used to encrypt the values ​​of each key in the multi-value mapping table using a quantum-resistant public key encryption algorithm based on the client's quantum-resistant public key, thereby generating an initial encrypted multi-value mapping table; it then uses the server's secret key and a quantum-resistant pseudo-random function to encrypt each ciphertext in the initial encrypted multi-value mapping table, thereby generating a pseudo-random encrypted multi-value mapping table; finally, it generates a target encrypted multi-value mapping table based on the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table.

[0092] Optionally, the first generation module is further configured to use a hash function to map each key-value pair in the multi-value mapping table to a preset integer space to obtain a hash table; after filtering each index in the hash table, a target index that meets the preset conditions is obtained; the element of the target index in the hash table is pushed onto a stack to obtain an XOR filter stack; and based on the quantum-resistant public key, a quantum-resistant public key encryption algorithm is used to encrypt each element in the XOR filter stack to generate an initial encrypted multi-value mapping table.

[0093] Optionally, the first generation module is also used to perform an XOR operation on the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table; and to randomly fill the encrypted multi-value mapping table after the XOR operation to obtain the target encrypted multi-value mapping table.

[0094] Optionally, the query module 120 is also used to obtain the corresponding quantum-resistant pseudo-random tag according to the query request; match each ciphertext in the target encrypted multi-value mapping table according to the quantum-resistant pseudo-random tag to obtain the target ciphertext corresponding to the quantum-resistant pseudo-random tag, and determine the encrypted multi-value query result set containing the target ciphertext.

[0095] Figure 9 A functional module diagram of another quantum-resistant encrypted multi-value query device provided in an embodiment of this application. Applied to a client, such as... Figure 9 As shown, the quantum-resistant encrypted multi-value query device 200 includes: The second acquisition module 210 is used to acquire the secret key of the server; The second generation module 220 is used to encrypt the target keyword using the server's secret key and the server's anti-quantum pseudo-random function to generate a query request; The sending module 230 is used to send a query request to the server so that the server can query the target encrypted multi-value mapping table according to the query request and obtain an encrypted multi-value query result set; wherein, the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated by the server in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table. The receiving module 240 is used to receive the encrypted multi-value query result set returned by the server; The decryption module 250 is used to decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with.

[0096] Optionally, the decryption module 250 is also used to decrypt the encrypted multi-value query result set using a quantum-resistant private key decryption algorithm based on the client's quantum-resistant private key to obtain the decryption result; if the decryption result matches the position of the target keyword, it is determined that the target keyword has not been tampered with; if the decryption result does not match the position of the target keyword, it is determined that the target keyword has been tampered with.

[0097] Optionally, the sending module 230 is also configured to send a query request to the server again if it is determined that the target keyword has been tampered with, so that the server can query the target encrypted multi-value mapping table again according to the query request and obtain a new encrypted multi-value query result set.

[0098] The above-described device is used to execute the method provided in the foregoing embodiments, and its implementation principle and technical effect are similar, so they will not be described again here.

[0099] These modules can be one or more integrated circuits configured to implement the above methods, such as one or more Application Specific Integrated Circuits (ASICs), one or more microprocessors, or one or more Field Programmable Gate Arrays (FPGAs). Alternatively, when a module is implemented using processing element scheduler code, the processing element can be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling program code. Furthermore, these modules can be integrated together as a system-on-a-chip (SOC).

[0100] This application also provides a possible implementation of a quantum-resistant encrypted multi-value query system. The quantum-resistant encrypted multi-value query system includes: a client-side key management unit, a server-side obfuscation construction unit, a quantum-resistant encryption operation unit, a dynamic verification coordination unit, and a secure transmission channel. Specifically, the client-side key management unit is used to generate, store, and distribute quantum-resistant key pairs based on lattice cryptography; the server-side obfuscation construction unit is used to construct an XOR filtering stack and a hash queue structure using large integer random parameters; the quantum-resistant encryption operation unit is used to execute a public-key encryption algorithm based on the LWE problem and pseudo-random padding operations; the dynamic verification coordination unit is used to manage query request generation, metadata matching and verification, and re-query triggering mechanisms; and the secure transmission channel provides a key distribution and ciphertext transmission channel guaranteed by the TLS 1.3 protocol.

[0101] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A quantum-resistant encrypted multi-value query method, characterized in that, Applied to the server side, the method includes: Obtain a query request sent by the client for the target keyword; the query request is a request generated by the client using the server's secret key and the server's quantum-resistant pseudo-random function to encrypt the target keyword; Based on the query request, the target encrypted multi-value mapping table is queried to obtain a set of encrypted multi-value query results; the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table. The encrypted multi-value query result set is returned to the client so that the client can decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with.

2. The method according to claim 1, characterized in that, Before obtaining the query request for the target keyword sent by the client, the method further includes: Based on the client's quantum-resistant public key, a quantum-resistant public key encryption algorithm is used to encrypt the value of each key in the multi-value mapping table to generate an initial encrypted multi-value mapping table; Based on the server's secret key, the server's quantum-resistant pseudo-random function is used to encrypt each ciphertext in the initial encrypted multi-value mapping table to generate a pseudo-random encrypted multi-value mapping table. A target encrypted multi-value mapping table is generated based on the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table.

3. The method according to claim 2, characterized in that, The step of encrypting the values ​​of each key in the multi-value mapping table using a quantum-resistant public key encryption algorithm based on the client's quantum-resistant public key to generate an initial encrypted multi-value mapping table includes: A hash function is used to map each key-value pair in the multi-value mapping table to a preset integer space to obtain a hash table; After filtering each index in the hash table, target indexes that meet preset conditions are obtained; Push the element at the target index in the hash table onto the stack to obtain the XOR filter stack; Based on the quantum-resistant public key, the quantum-resistant public key encryption algorithm is used to encrypt each element in the XOR filter stack to generate the initial encrypted multi-value mapping table.

4. The method according to claim 2, characterized in that, The step of generating a target encrypted multi-value mapping table based on the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table includes: Perform an XOR operation on the initial encrypted multi-value mapping table and the pseudo-random encrypted multi-value mapping table; The target encrypted multi-value mapping table is obtained by randomly filling the encrypted multi-value mapping table after the XOR operation.

5. The method according to claim 1, characterized in that, The step of querying the target encrypted multi-value mapping table according to the query request to obtain an encrypted multi-value query result set includes: Based on the query request, obtain the corresponding quantum-resistant pseudo-random tag; Based on the anti-quantum pseudo-random label, each ciphertext in the target encrypted multi-value mapping table is matched to obtain the target ciphertext corresponding to the anti-quantum pseudo-random label, and the set of encrypted multi-value query results containing the target ciphertext is determined.

6. A quantum-resistant encrypted multi-value query method, characterized in that, Applied to a client, the method includes: Obtain the server's secret key; Based on the server's secret key, the target keyword is encrypted using the server's quantum-resistant pseudo-random function to generate a query request; The query request is sent to the server so that the server queries the target encrypted multi-value mapping table according to the query request and obtains an encrypted multi-value query result set; wherein, the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated by the server in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table. Receive the encrypted multi-value query result set returned by the server; The encrypted multi-value query result set is decrypted to obtain the decryption result, and it is determined whether the target keyword has been tampered with.

7. The method according to claim 6, characterized in that, The step of receiving the encrypted multi-value query result set, decrypting the encrypted multi-value query result set to obtain the decryption result, and determining whether the target keyword has been tampered with, further includes: Based on the client's quantum-resistant private key, the encrypted multi-value query result set is decrypted using a quantum-resistant private key decryption algorithm to obtain the decryption result; If the decryption result matches the location of the target keyword, then it is determined that the target keyword has not been tampered with; If the decryption result does not match the position of the target keyword, then the target keyword is determined to have been tampered with.

8. The method according to claim 6, characterized in that, The method further includes: If it is determined that the target keyword has been tampered with, the query request is sent to the server again, so that the server queries the target encrypted multi-value mapping table again according to the query request to obtain a new encrypted multi-value query result set.

9. A quantum-resistant encrypted multi-value query device, characterized in that, Applied to the server side, the device includes: The first acquisition module is used to acquire a query request for a target keyword sent by the client; the query request is a request generated by the client encrypting the target keyword using the server's secret key and the server's anti-quantum pseudo-random function. The query module is used to query the target encrypted multi-value mapping table according to the query request and obtain an encrypted multi-value query result set; the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table. The return module is used to return the encrypted multi-value query result set to the client, so that the client can decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with.

10. A quantum-resistant encrypted multi-value query device, characterized in that, Applied to a client, the device includes: The second acquisition module is used to acquire the server's secret key; The second generation module is used to encrypt the target keyword using the server's secret key and the server's quantum-resistant pseudo-random function to generate a query request; The sending module is used to send the query request to the server, so that the server queries the target encrypted multi-value mapping table according to the query request and obtains an encrypted multi-value query result set; wherein, the target encrypted multi-value mapping table is an encrypted multi-value mapping table generated by the server in advance by encrypting the client's quantum-resistant public key and the multi-value mapping table; A receiving module is used to receive the encrypted multi-value query result set returned by the server; The decryption module is used to decrypt the encrypted multi-value query result set, obtain the decryption result, and determine whether the target keyword has been tampered with.

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