Strong security ciphertext retrieval method and system supporting result pattern leakage and hiding

Abstract

The present invention discloses a strong security ciphertext retrieval method and system that supports result pattern leakage hiding, comprising two parts: a subset predicate encryption method capable of hiding vectors and a strong security ciphertext retrieval method capable of hiding result pattern leakage hiding. The said subset predicate encryption method capable of hiding vectors implements a strong security privacy discrimination method for vector subsets, by performing a one-time encryption and request process on the vector subset, thereby judging whether the predicate set belongs to the original overall attribute set, and will not leak relevant privacy information. The said strong security ciphertext retrieval method capable of hiding result pattern leakage hiding solves the privacy leakage problem in the member detection and matching process in the traditional connection keyword searchable encryption scheme, by performing member existence discrimination on the label set of the keyword document pair, and in this process, the result pattern association information between the keyword and the document will not be leaked, thereby effectively enhancing the security of the system.

Description

Technical Field

[0001] The present invention belongs to the field of secure retrieval of secret databases in applied cryptography, and relates to a subset predicate encryption strategy capable of hiding vectors, a highly secure ciphertext retrieval system and equipment, and more particularly to a highly secure ciphertext retrieval method and system that supports result pattern leakage hiding. Background Art

[0002] In recent years, with the rapid development of network technology, the amount of data generated and stored has continued to increase, posing a significant challenge to traditional local storage methods. This has led to the emergence of cloud storage technology. As an advanced data storage and management method, cloud storage provides users with nearly unlimited storage resources and powerful computing power by storing data on remote servers, greatly facilitating the development of services for individuals, businesses, and organizations. However, traditional cloud storage models pose certain risks in terms of data privacy protection, as data is often stored in plaintext on cloud servers, which can lead to data leaks and unauthorized access.

[0003] While traditional data encryption technologies effectively ensure data confidentiality, they also make retrieval extremely difficult. A common solution is for users to encrypt locally stored plaintext data and upload it to a cloud storage server. When retrieval is required, the data is first downloaded locally, decrypted, and then retrieved. However, this approach wastes significant communication and computing resources on non-target files. Symmetric searchable encryption technology has emerged to address this issue.

[0004] Searchable encryption is a technology that enables efficient search on encrypted data. It allows users to perform keyword searches while maintaining data encryption, without exposing the plaintext content. Linked keyword search technology further allows users to use multiple keywords or phrases in a search query, resulting in more targeted and relevant search results. Dynamic searchable encryption allows clients to securely update database content.

[0005] However, in order to achieve high performance, current dynamic searchable encryption schemes for connection keywords have some problems, such as the inability to guarantee forward and backward security, or the existence of result pattern leakage issues. These issues may leak some information to the server, including the query itself and the database content. Recent studies have shown that in practical applications, this partial leakage can sometimes be exploited, especially when the attacker has some auxiliary information. Therefore, the study of result pattern leakage in dynamic searchable encryption schemes for connection keywords is of great significance. How to achieve secure and efficient connection keyword retrieval and ensure the privacy protection of result patterns during the retrieval process is also an urgent problem that needs to be solved in this field. Summary of the Invention

[0006] In view of the above requirements for data security, information leakage retrieval, ciphertext security detection, etc. and the drawbacks of the above traditional solutions, the present invention provides a strong security ciphertext retrieval method and system that supports result pattern leakage hiding.

[0007] The technical solution adopted by the method of the present invention is: a strong security ciphertext retrieval method that supports result pattern leakage hiding, the participating entities include data users and cloud storage servers; including a subset predicate encryption method for hidden vectors and a strong security ciphertext retrieval method that supports result pattern leakage hiding;

[0008] The subset predicate encryption method for hiding vectors is specifically implemented in the following stages:

[0009] In the encryption initialization phase, the security parameter λ and the vector dimension n are input. The initialization process generates the public parameter par and the master key information msk, and provides the public parameters to the participating entities.

[0010] In the index generation phase, the data user inputs the public parameter par, the master key information msk, and the predicate set S v , and finally output the index ciphertext tk v , and send it to the cloud storage server;

[0011] In the encryption phase, first input the public parameter par, the plaintext message symbol m, and the overall attribute set S k , and finally output the encrypted ciphertext ct k ;

[0012] In the request phase, the cloud storage server inputs the public parameter par and the encrypted ciphertext ct k , index ciphertext tk v , and finally output the decrypted plaintext message symbol m or the termination symbol ⊥ if decryption fails.

[0013] As an optimization, in the encryption initialization phase, the security parameter λ∈N is input, the vector dimension size is an integer n∈N, G1, G2, G T They are three multiplication groups, the order of the group is a large prime number p, g1 is the generator of group G1, g2 is the generator of group G2, g t For group G T Generator, bilinear map e:G1×G2→G T , hash function H j (.), where 1≤j≤s, s is the hash function H j (.); select random numbers x1, x2, ..., x n ,μ,w∈Z p ={1,2,...,p-1}, calculate the generated value The final public parameters are set to Master key msk={x1,x2,…,x n ,μ,w}.

[0014] As a preference, during the index generation phase, public parameters are input Input master key msk={x1,x2,…,x n ,μ,w}, and the predicate vector S v ={v1,v2,…,v n}, data users choose random numbers u,v∈Z p ={1,2,...,p-1}, calculate Final output index ciphertext

[0015] As a preference, in the encryption phase, the public parameters are input The plaintext message m to be encrypted, and the overall attribute vector S k ={k1,k2,…,k n}, choose a random number κ∈Z p ={1,2,...,p-1}, the cloud storage server performs the encryption process and calculates ct0=ξ κ m, as well as The final setting generates the encrypted ciphertext Where 1≤i≤n.

[0016] As a preference, in the request phase, the cloud storage server inputs the system public parameters Index ciphertext And encrypted ciphertext Execute the following request process: First calculate The final calculation is If the final predicate vector Then output the plaintext message m, otherwise output the operation termination symbol ⊥.

[0017] Preferably, the strong security ciphertext retrieval method with result pattern leakage concealment includes the following stages:

[0018] In the retrieval initialization phase, the security parameter λ and the vector dimension n are input. The initialization process generates the public parameter par, the secret state information st, and initializes the empty encryption database EDBEDB = (Tset, Lset), where Tset is a key-value pair storage structure to cache the encryption index, and Lset stores the corresponding cross-index ciphertext.

[0019] In the ciphertext index update phase, the data user inputs the public parameter par, the secret state information st, the keyword-document pair to be updated (w, id), and the update operator op. The cloud storage server inputs the encrypted database EDB. Finally, the data user saves the updated state information st', and the cloud storage server inputs the updated encrypted index EDB' = (Tset, Lset).

[0020] In the connection keyword search phase, the data user inputs the public parameter par, the secret state information st, and the connection keyword request q to be searched = (w1∧…∧w x ), the cloud storage server inputs the encrypted database EDB, and finally the cloud storage server returns the corresponding search results to the data user.

[0021] As a preference, in the retrieval initialization phase, the data user inputs the security parameter λ∈N, the initialization vector size n∈N, and generates the relevant public parameters Master key msk={x1,x2,…,x n ,μ,w}, select a random number k,k x ,k y ,k z ,k t ∈Z p ={1,2,...,p-1}, initialize the counter set Cnt w , and finally set the user's privacy status st=(k,k x ,k y ,k z ,k t ,msk,Cnt w The cloud storage server initializes the empty encrypted database Tset and Lset structures for subsequent use, and sets the initial encrypted database EDB = (Tset, Lset).

[0022] As a preference, during the ciphertext index update phase, the data user enters the public parameter Privacy state st=(k,k x ,k y ,k z ,k t ,msk,Cnt w ), the keyword-document pair to be updated (w, id), the update operator op, performs the following encryption operation: calculate the update address addr←F p (k t ,w||Cnt w ||0) and ciphertext val←(id||op)⊕F p (k t,w||Cnt w ||1), where F p For a secure pseudo-random function, the counter Cnt w Synchronously increment by 1 to ensure that the updated index is not associated with the previous search token, achieving forward security. The op includes add or delete operations to distinguish the update operation of the ID. The final decryption is performed by the data user to ensure backward security.

[0023] Data users generate labels σ←H(k,F p (k y ,id||op)+H(k,F p (k z ,w||Cnt w ), and cross-index tag tag←H(k,F p (k x ,w)+H(k,F p (k y ,id||op), where H(.) is a hash function, and finally the encrypted index (addr,val,σ,tag) is sent to the cloud storage server; after receiving the encrypted index, the cloud storage server performs an update operation and stores the ciphertext value in the Tset structure, that is, Tset[addr]=(val,σ), and further adds the tag value to the cross-index attribute vector S k And perform encryption operation to generate the corresponding encrypted ciphertext ct k , and set Lset = ct k Finally, the cloud storage server outputs the updated encryption index EDB'=(Tset, Lset).

[0024] As an example, in the connection keyword search phase, the data user first requests q=(w1∧…∧w n ) Generate the corresponding search token list stokenlist, xtokenlist; where stokenlist contains the search addresses of all keywords w1 is the value of the counter corresponding to keyword w1; xtokenlist contains the remaining keywords w2,…,w n Cross-token xtkn i,j =H(k,F p (k x ,w i ))-H(k,F p (k z ,w1||j)), i∈[2,n];Finally, the user sends the generated search token lists stokenlist and xtokenlist to the cloud storage server;

[0025] After receiving the search token, the cloud storage server executes the search operation and finally returns the search result Reslist to the data user. Reslist contains all the data that meet the search request q=(w1∧…∧w n )'s search results (y,val y ), y∈[1, tokenlist.size], val y is the corresponding search ciphertext value; when the data user receives the returned search results, the decryption operation (id||op)←F(k t ,w1||y||1)⊕val y ; If op is an add operation, the data user adds the id to the final result list; if op is a delete operation, the data user deletes the id from the final result list.

[0026] The technical solution adopted by the system of the present invention is: a strong security ciphertext retrieval system that supports result pattern leakage and hiding, comprising:

[0027] one or more processors;

[0028] A storage device is used to store one or more programs, which, when executed by the one or more processors, enables the one or more processors to implement the strong security ciphertext retrieval method that supports result pattern leakage hiding.

[0029] Compared with the prior art, the advantages and positive effects of the present invention are mainly reflected in the following aspects:

[0030] (1) The present invention proposes a subset predicate encryption method that can hide vectors, and realizes a strong security privacy judgment method for vector subsets. By implementing a one-time encryption and request process for vector subsets, it further judges whether the subset predicate set belongs to the original large attribute set, avoiding the privacy leakage problem in the judgment process of traditional schemes, and further improving the security of ciphertext data search.

[0031] (2) The present invention provides a strong security ciphertext retrieval method with result pattern leakage concealment, which solves the privacy leakage problem in the member detection and matching process of the traditional connection keyword searchable encryption scheme. The invention performs member existence judgment on the label set of the keyword-document pair, and the result pattern association information between the keyword and the document will not be leaked in the process, thereby effectively enhancing the security of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The technical solution of this invention is further illustrated below using embodiments and specific implementation methods. In addition, some drawings are also used in the process of illustrating the technical solution. For those skilled in the art, other drawings and the intention of the invention can be obtained based on these drawings without inventive efforts.

[0033] Figure 1 This is a principle framework diagram of the method in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of a subset predicate encryption method capable of hiding vectors in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the principle of strongly secure ciphertext retrieval with result pattern leakage concealment in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding and implementation of the present invention by those skilled in the art, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the implementation examples described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0037] Please see Figure 1 This embodiment provides a strong security ciphertext retrieval method that supports result pattern leakage hiding. Participating entities include data users and cloud storage servers; it includes a subset predicate encryption method for hidden vectors and a strong security ciphertext retrieval method that supports result pattern leakage hiding.

[0038] Please see Figure 2 In one embodiment, the subset predicate encryption method for the hidden vector includes the following stages:

[0039] In the encryption initialization phase, the security parameter λ and the vector dimension n are input. The initialization process generates the public parameter par and the master key information msk, and provides the public parameters to the system participating entities.

[0040] In one embodiment, the input security parameter λ∈N, the vector dimension size is an integer n∈N, G1, G2, G T They are three multiplication groups, the order of the group input security parameter λ∈N, the vector dimension size is an integer n∈N, G1, G2, G T They are three multiplication groups, the order of the group is a large prime number p, g1 is the generator of group G1, g2 is the generator of group G2, g t For group G T Generator, bilinear map e:G1×G2→G T , hash function H j (.), where 1≤j≤s, s is the hash function H j(.); select random numbers x1, x2, ..., x n ,μ,w∈Z p ={1,2,...,p-1}, calculate the generated value The final public parameters are set to Master key msk={x1,x2,…,x n ,μ,w}.

[0041] In the index generation phase, the data user inputs the public parameter par, the master key information msk, and the predicate set S v , and finally output the index ciphertext tk v , and send it to the cloud storage server;

[0042] In one embodiment, during the index generation phase, public parameters are input Input master key msk={x1,x2,…,x n ,μ,w}, and the predicate vector S v ={v1,v2,…,v n}, data users choose random numbers u,v∈Z p ={1,2,...,p-1}, calculate Final output index ciphertext In the encryption phase, due to public key encryption, entities that have public information can perform encryption operations. The cloud storage server performs this process. First, input the public parameter par, the plaintext message symbol m, and the overall attribute set S k , and finally output the encrypted ciphertext ct k ;

[0043] In one embodiment, the public parameters are input The plaintext message m to be encrypted, and the overall attribute vector S k ={k1,k2,…,k n}, choose a random number κ∈Z p ={1,2,...,p-1}, the cloud storage server performs the encryption process and calculates ct0=ξ κ m, as well as Where 1≤i≤n, the final set of generated encrypted ciphertext Where 1≤i≤n.

[0044] In the request phase, the cloud storage server inputs the public parameter par and the encrypted ciphertext ct k , index ciphertext tk v , and finally output the decrypted plaintext message symbol m or the termination symbol ⊥ if decryption fails.

[0045] In one embodiment, the cloud storage server inputs the system public parameters Index ciphertext And encrypted ciphertext Where 1≤i≤n, execute the following request process: first calculate The final calculation is If the final predicate vector Then output the plaintext message m, otherwise output the operation termination symbol ⊥.

[0046] Please see Figure 3 This embodiment provides a strong security ciphertext retrieval method with result pattern leakage concealment, and its specific implementation includes the following stages:

[0047] In the retrieval initialization phase, the security parameter λ and the vector dimension m are input. The initialization process generates the public parameter par, the secret state information st, and initializes the empty encrypted database EDBEDB = (Tset, Lset), where Tset is a key-value pair storage structure to cache the encryption index, and Lset stores the corresponding cross-index ciphertext.

[0048] In one embodiment, the data user inputs the security parameter λ∈N, the initialization vector size n∈N, and generates the relevant public parameters Master key msk={x1,x2,…,x n ,μ,w}, select a random number k,k x ,k y ,k z ,k t ∈Z p ={1,2,...,p-1}, initialize the counter set Cnt w , and finally set the user's privacy status st=(k,k x ,k y ,k z ,k t ,msk,Cnt w The cloud storage server will initialize the empty encrypted database Tset and Lset structures for subsequent use, and set the initial encrypted database EDB = (Tset, Lset).

[0049] In the ciphertext index update phase, the data user inputs the public parameter par, the secret state information st, the keyword-document pair to be updated (w, id), the update operator op, and the cloud storage server inputs the encrypted database EDB. Finally, the data user saves the updated state information st', and the cloud storage server inputs the updated encrypted index EDB' = (Tset, Lset).

[0050] In one embodiment, the data user enters the public parameters Privacy state st=(k,k x ,k y ,k z ,k t ,msk,Cnt w ), the keyword-document pair to be updated (w, id), the update operator op, performs the following encryption operation: calculate the update address addr←F p (k t ,,w||Cnt w ||0) and ciphertext val←(id||op)⊕F p (k t ,w||Cnt w ||1), where F p For a secure pseudo-random function, the counter Cnt w The updated index is synchronously incremented by 1 to ensure that it is not associated with the previous search token, achieving forward security. The op includes add or delete operations to distinguish the update operation of the id. The final decryption is performed by the data user himself, ensuring backward security.

[0051] In addition, the data user generates a label σ←H(k,F p (k y ,id||op)+H(k,F p (k z ,w||Cnt w ), and cross-index tag tag←H(k,F p (k x ,w)+H(k,F p (k y ,id||op), where H(.) is a hash function, and finally the encrypted index (addr,val,σ,tag) is sent to the cloud storage server. After receiving the encrypted index, the cloud storage server performs an update operation and stores the ciphertext value in the Tset structure, that is, Tset[addr]=(val,σ), and further adds the tag value to the cross-index attribute vector S k And perform encryption operation to generate the corresponding encrypted ciphertext ct k , and set Lset = ct k Finally, the cloud storage server outputs the updated encrypted index EDB'=(Tset, Lset).

[0052] In the connection keyword search phase, the data user inputs the public parameter par, the secret state information st, and the connection keyword request q to be searched = (w1∧…∧w n), the cloud storage server inputs the encrypted database EDB, and finally the cloud storage server returns the corresponding search results to the data user, effectively preventing the privacy leakage of the result pattern during the search process and enhancing the security of the system.

[0053] In one embodiment, the data user first requests q=(w1∧…∧w n ) Generate the corresponding search token list stokenlist, xtokenlist. Among them, stokenlist contains the search address saddr of all keywords w1 j ←F p (k t ,w1||j||0), where is the value of the counter corresponding to keyword w1. xtokenlist contains the remaining keywords w2,…,w n Cross-token xtkn i,j =H(k,F p (k x ,w i ))-H(k,F p (k z ,w1||j)), where Finally, the user sends the generated search token lists stokenlist and xtokenlist to the cloud storage server.

[0054] After receiving the search token, the cloud storage server executes the search operation and finally returns the search result Reslist to the data user. Reslist contains all the data that meet the search request q=(w1∧…∧w n )'s search results (y,val y ), where y∈[1,stokenlist.size], val y is the corresponding search ciphertext value. When the data user receives the returned search results, the decryption operation (id||op)←F(k t ,w1||y||1)⊕val y If op is an add operation, the data user adds the id to the final result list; if op is a delete operation, the data user deletes the id from the final result list. In the above-mentioned connection keyword search process, the present invention effectively prevents the cloud storage server from collecting result pattern privacy information based on the subset predicate encryption strategy that can hide vectors, effectively improving the security of the system.

[0055] This embodiment also provides a strong security ciphertext retrieval system that supports result pattern leakage hiding, including: one or more processors; a storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, the one or more processors implement the strong security ciphertext retrieval method that supports result pattern leakage hiding.

[0056] The present invention solves the problem of privacy leakage of result patterns in traditional connection keyword retrieval schemes, designs a subset predicate encryption strategy that can hide vectors, and implements a strong security privacy judgment method for vector subsets; the application of this method in the field of ciphertext retrieval can realize strong security ciphertext retrieval with result pattern leakage hidden, solves the privacy leakage problem in the member detection and matching process in traditional connection keyword searchable encryption schemes, and further improves the security of the system.

[0057] The present invention can provide users with a reliable and secure ciphertext retrieval method in cloud storage, data security, blockchain, industrial Internet and other fields.

[0058] It should be understood that the above description of the preferred embodiment is relatively detailed and cannot be regarded as limiting the scope of protection of the patent of the present invention. Under the guidance of the present invention, ordinary technicians in this field can also make substitutions or modifications without departing from the scope of protection of the claims of the present invention, which all fall within the scope of protection of the present invention. The scope of protection requested by the present invention shall be based on the attached claims.

Claims

1. A strong secure ciphertext retrieval method that supports result pattern leakage and concealment, wherein the participating entities include data users and cloud storage servers; the method is characterized by: Including subset predicate encryption method for hiding vectors and strong security ciphertext retrieval method with result pattern leakage hiding; The subset predicate encryption method for hiding vectors is specifically implemented in the following stages: In the encryption initialization phase, the security parameter λ and the vector dimension n are input. The initialization process generates the public parameter par and the master key information msk, and provides the public parameters to the participating entities. In the index generation phase, the data user inputs the public parameter par, the master key information msk, and the predicate vector set S v , and finally output the index ciphertext tk v , and send it to the cloud storage server; In the encryption phase, first input the public parameter par, the plaintext message symbol m, and the overall attribute vector set S k , and finally output the encrypted ciphertext ct k ; In the request phase, the cloud storage server inputs the public parameter par and the encrypted ciphertext ct k , index ciphertext tk v , if the final predicate vector set Then output the plaintext message m, otherwise output the operation termination symbol ⊥; The strong security ciphertext retrieval method with result pattern leakage concealment specifically includes the following stages: In the retrieval initialization phase, the security parameter λ and the vector dimension n are input. The initialization process generates the public parameter par, the secret state information st, and initializes the empty encrypted database EDB = (Tset, Lset), where Tset is a key-value pair storage structure to cache the encrypted index, and Lset stores the corresponding cross-index ciphertext. In the ciphertext index update phase, the data user inputs the public parameter par, the secret state information st, the keyword-document pair to be updated (w, id), the update operator op, and the cloud storage server inputs the encrypted database EDB. Finally, the data user saves the updated state information st'; the data user generates a cross-index tag and further adds the tag value to the cross-index attribute vector set S k And perform encryption operation to generate the corresponding encrypted ciphertext ct k , and set Lset = ct k , finally the cloud storage server outputs the updated encrypted index EDB'=(Tset, Lset); In the connection keyword search phase, the data user inputs the public parameter par, the secret state information st, and the connection keyword request q to be searched = (w1∧…∧w n ), the cloud storage server inputs the encrypted database EDB, and finally the cloud storage server returns the corresponding search results to the data user.

2. The method for strongly secure ciphertext retrieval supporting result pattern leakage and concealment according to claim 1, characterized in that: In the encryption initialization phase, the security parameter λ∈N is input, the vector dimension size is an integer n∈N, G1, G2, G T They are three multiplication groups, the order of the group is a large prime number p, g1 is the generator of group G1, g2 is the generator of group G2, g t For group G T Generator, bilinear map e:G1×G2→G T , hash function H j (.), where 1≤j≤s, s is the hash function H j (.); select random numbers x1, x2, ..., x n ,μ,w∈Z p ={1,2,...,p-1}, calculate the generated value The final public parameters are set to Master key msk={x1,x2,…,x n ,μ,w}.

3. The strong security ciphertext retrieval method supporting result pattern leakage hiding according to claim 2 is characterized by: During the index generation phase, enter public parameters Input master key msk={x1,x2,…,x n ,μ,w}, and the predicate vector set S v ={v1,v2,…,v n }, data users choose random numbers u,v∈Z p ={1,2,...,p-1}, calculate Final output index ciphertext 4. The method for strongly secure ciphertext retrieval supporting result pattern leakage and concealment according to claim 3, characterized in that: In the encryption phase, public parameters are input The plaintext message m to be encrypted, and the overall attribute vector set S k ={k1,k2,…,k n }, choose a random number κ∈Z p ={1,2,...,p-1}, the cloud storage server performs the encryption process and calculates ct0=ξ κ m, as well as The final setting generates the encrypted ciphertext Where 1≤i≤n.

5. The strong security ciphertext retrieval method supporting result pattern leakage hiding according to claim 4 is characterized in that: In the request phase, the cloud storage server inputs the system public parameters Index ciphertext And encrypted ciphertext Execute the following request process: First calculate The final calculation is If the final predicate vector set Then output the plaintext message m, otherwise output the operation termination symbol ⊥.

6. The method for strongly secure ciphertext retrieval supporting result pattern leakage and concealment according to claim 5, characterized in that: In the retrieval initialization phase, the data user inputs the security parameter λ∈N, the initialization vector size n∈N, and generates the relevant public parameters Master key msk={x1,x2,...,x n , μ, w}, select random number k, k x , k y , k z , k t ∈Z p ={1, 2, ..., p-1}, initialize the counter set Cnt w , finally set the user's privacy status st=(k,k x , k y , k z , k t ,msk,Cnt w ); The cloud storage server initializes the empty encryption database Tset and Lset structures for subsequent use, and sets the initial encryption database EDB = (Tset, Lset).

7. The strong security ciphertext retrieval method supporting result pattern leakage hiding according to claim 6 is characterized in that: During the ciphertext index update phase, the data user enters the public parameters Privacy state st = (k, k x , k y , k z , k t ,msk,Cnt w ), the keyword-document pair to be updated (w, id), the update operator op, performs the following encryption operation: calculate the update address addr←F p (k t ,w||Cnt w ||0) and ciphertext Among them F p For a secure pseudo-random function, the counter Cnt w Synchronously increment by 1 to ensure that the updated index is not associated with the previous search token, achieving forward security. The op includes add or delete operations to distinguish the update operation of the ID. The final decryption is performed by the data user to ensure backward security. Data users generate labels σ←H(k, F p (k y , id||op)+H(k,F p (k z ,w||Cnt w ), and cross-index tag tag←H(k,F p (k x ,w)+H(k,F p (k y , id||op), where H(.) is a hash function, and finally the encrypted index (addr, val, σ, tag) is sent to the cloud storage server; after receiving the encrypted index, the cloud storage server performs an update operation and stores the ciphertext value in the Tset structure, that is, Tset[addr] = (val, σ), and further adds the value of tag to the cross-index attribute vector set S k And perform encryption operation to generate the corresponding encrypted ciphertext ct k , and set Lset = ct k Finally, the cloud storage server outputs the updated encryption index EDB'=(Tset, Lset).

8. The method for strongly secure ciphertext retrieval supporting result pattern leakage and concealment according to claim 7, characterized in that: In the connection keyword search phase, the data user first requests q=(w1^...^w n ) Generate the corresponding search token list stokenlist, xtokenlist; where stokenlist contains the search address saddr of all keywords w1 j ←F p (k t , w1||j||0), is the value of the counter corresponding to keyword w1; xtokenlist contains the remaining keywords w2, ..., w n Cross-token xtkn i,j =H(k,F p (k x , w i ))-H(k,F p (k z , w1||j)), i∈[2,n]; finally, the user sends the generated search token lists stokenlist and xtokenlist to the cloud storage server; After receiving the search token, the cloud storage server executes the search operation and finally returns the search result Reslist to the data user. Reslist contains all the data that meet the search request q=(w1∧…∧w n )'s search results (y,val y ), y∈[1, tokenlist.size], val y is the corresponding search ciphertext value; when the data user receives the returned search results, the decryption operation is finally performed If op is an add operation, the data user adds the id to the final result list; if op is a delete operation, the data user deletes the id from the final result list.

9. A strong secure ciphertext retrieval system that supports result pattern leakage and hiding, characterized by: include: one or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, enables the one or more processors to implement a strong security ciphertext retrieval method that supports result pattern leakage hiding as described in any one of claims 1 to 8.

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