A tobacco retail customer credit data security sharing method based on proxy re-encryption

Abstract

The application relates to the technical field of network space security, and discloses a tobacco retail customer credit data security sharing method based on proxy re-encryption, a credit system is established, a tobacco retail customer logs in to the credit system in a password verification mode, initialization processing is carried out after data is sent, a key is generated before data transmission, n pieces of re-encryption key slice vectors of 26 group elements are generated, after the re-encryption key slices are generated, encrypted data is output, and slice decryption is carried out; in the ciphertext forwarding stage, the single-point failure problem of a proxy server in traditional proxy re-encryption technology is avoided, the single-point failure of a key generation center in traditional identity-based cryptography and the key escrow problem are avoided in the key distribution stage by using double threshold key distribution technology, and an end-to-end encryption data encryption method is realized; even if the data is intercepted in the transmission process, the data cannot be decrypted by a third party without the key.

Description

Technical Field

[0001] This invention relates to the field of cyberspace security technology, and more specifically to a method for securely sharing tobacco retail customer credit data based on proxy re-encryption. Background Technology

[0002] The credit supervision system of the tobacco industry still faces some problems. Currently, some tobacco retail customers have dishonest issues, and it is impossible to correctly judge whether a tobacco retail customer is trustworthy without knowing their situation. Therefore, it is necessary to create a credit information inquiry system. Users can log in to the system to understand the credit index of a tobacco retail customer, thereby helping users choose different tobacco retail customers and also playing a supervisory role over tobacco retail customers. In the process of establishing the credit information inquiry system, tobacco retail customers need to submit detailed credit data such as their business status, complaint handling, administrative penalties, tobacco information, and consumption reminders. These data will be assessed and publicly released by a dedicated credit audit system. To prevent the leakage of merchants' credit information and malicious assessment operations, how to complete the credit audit process flexibly and controllably while ensuring privacy is an urgent problem to be solved.

[0003] Nowadays, data sharing between data senders and receivers is generally conducted one-to-one, and both parties encrypt the data during transmission to prevent it from being stolen. However, simple encryption cannot guarantee the security of data. With the continuous evolution of network attack methods, traditional data encryption measures can no longer meet current security needs. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a method for secure sharing of tobacco retail customer credit data based on proxy re-encryption, so as to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for securely sharing tobacco retail customer credit data based on proxy re-encryption, comprising the following steps:

[0006] Step S1: Establish a credit system. Tobacco retail customers log in to the credit system using password verification.

[0007] Step S2: After logging into the credit system, initialization is performed. During data initialization, the Setup algorithm is executed to generate initial system parameters.

[0008] Step S3: Call the Extract algorithm to generate n key fragments. Each key fragment consists of a vector of 12 group elements. Send the data containing the key fragments.

[0009] In step S4, during the data transmission of key fragments, after the re-encryption key system receives more than t key fragments, it executes the ReKeyGen algorithm after receiving all the key fragments to generate n re-encryption key fragment vectors with 26 group elements.

[0010] Step S5: After the re-encryption key system generates re-encryption key fragments, it executes the Enc algorithm, inputs the address of the data receiver, outputs encrypted data, and sends it to n proxy servers respectively.

[0011] Step S6: n proxy servers receive the encrypted data, execute the ReEnc algorithm, and each proxy server outputs a re-encrypted data fragment;

[0012] Step S7: After receiving more than t key fragments, the receiver waits to receive all the key fragments, executes the Dec algorithm for decryption, and uses re-encrypted ciphertext to integrate and collect more than t re-encrypted data for fragment decryption.

[0013] In a preferred embodiment, in step S1, the Setup algorithm is a system initialization algorithm that outputs random groups G1 and G2 of prime order q, and groups G1 and G2 satisfy a bilinear mapping e.

[0014] In a preferred embodiment, during the generation of key fragments and re-encryption key fragment vectors in steps S2 and S3, an update request is made after each generation. When the update request is executed, the node flag for generating key fragments and re-encryption key fragment vectors is discarded, and new node flags for key fragments and re-encryption key fragment vectors are generated. When the generated key fragments and re-encryption key fragment vectors are received, the new node flags replace the old node flags. When the generated key fragments and re-encryption key fragment vectors are not received and used, the old node flags continue to be used.

[0015] In a preferred embodiment, when replacing an old node identifier with a new one, the new node identifier is sent to the tobacco retail customer who is replacing the node identifier, and the new node identifier is recorded and publicized. When a new tobacco retail customer joins, a new node identifier is generated and bound to the newly joined tobacco retail customer. When a tobacco retail customer leaves the credit system, the customer's node identifier is marked. When the marking period reaches three months and the departing tobacco retail customer has not yet joined, the identity identifier is directly discarded and not redistributed.

[0016] In a preferred embodiment, in step S1, the credit system includes a main system containing credit data of tobacco retail customers and a subsystem for verification. When a tobacco retail customer logs into the system, they are connected to the verification system of the subsystem. After the customer's login verification is successful, the subsystem is connected to the main system, and the customer can connect to the main system and share information and data.

[0017] In a preferred embodiment, in step S6, the received data is decrypted using two storage devices for dual storage, and each re-encrypted data is stored in m data blocks when the two storage devices store the data. The two storage devices can communicate and transmit data to each other.

[0018] In a preferred embodiment, when two storage devices communicate, the number of data blocks corresponding to each re-encrypted data in the two storage devices is compared. When the number of data blocks corresponding to the re-encrypted data in the two storage devices is different, the data block with a larger number of data blocks is used instead of the data block with a smaller number of data blocks. When the number of data blocks is the same, the selection is random. After selecting the data block with a larger number of data blocks for each re-encrypted data, the data is decrypted.

[0019] In a preferred embodiment, in step S6, when collecting more than t re-encrypted data for fragment decryption, the Lagrange interpolation method is used to interpolate and combine the fragments of more than t re-encrypted data to perform decryption. The process is carried out when the number of keys is more than t, and no decryption is performed when the number of keys is t or less.

[0020] The technical effects and advantages of this invention are as follows:

[0021] 1. This invention avoids the single point of failure problem of proxy server in traditional proxy re-encryption technology during the ciphertext forwarding stage. It uses dual threshold key distribution technology to avoid the single point of failure and key custody problem of key generation center in traditional identity-based cryptography during the key distribution stage, and realizes an end-to-end encrypted data encryption method. Even if the data is intercepted during transmission, no third party without the key can decrypt the data.

[0022] 2. This invention uses proxy re-encryption technology, which can directly send user A's credit data to user B after re-encryption. Traditional encryption technology requires user A to decrypt the data to be analyzed and then re-encrypt it before sending it to user B. Compared with traditional encryption technology, this invention eliminates one decryption step and reduces server overhead.

[0023] 3. In this invention, tobacco retail customers send an update request when sending data, and the node flag generated by key fragmentation and re-encryption key fragmentation vector is marked as discarded. When tobacco retail customers share data normally, the node flag with the discarded flag is directly discarded. Therefore, tobacco retail customers use a new node identity every time they use the data, reducing the possibility of data leakage. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the proxy re-encryption data sharing process of the present invention. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The method for secure sharing of tobacco retail customer credit data based on proxy re-encryption involved in the present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] Reference Figure 1 This invention provides a method for securely sharing tobacco retail customer credit data based on proxy re-encryption, comprising the following steps:

[0028] Step S1: Establish a credit system. Tobacco retail customers log in to the credit system using password verification.

[0029] Step S2: After logging into the credit system, initialization is performed. During data initialization, the Setup algorithm is executed to generate initial system parameters.

[0030] Step S3: Call the Extract algorithm to generate n key fragments. Each key fragment consists of a vector of 12 group elements. Send the data containing the key fragments.

[0031] In step S4, during the data transmission of key fragments, after the re-encryption key system receives more than t key fragments, it executes the ReKeyGen algorithm after receiving all the key fragments to generate n re-encryption key fragment vectors with 26 group elements.

[0032] Step S5: After the re-encryption key system generates re-encryption key fragments, it executes the Enc algorithm, inputs the address of the data receiver, outputs encrypted data, and sends it to n proxy servers respectively.

[0033] Step S6: n proxy servers receive the encrypted data, execute the ReEnc algorithm, and each proxy server outputs a re-encrypted data fragment;

[0034] Step S7: After receiving more than t key fragments, the receiver waits to receive all the key fragments, executes the Dec algorithm for decryption, and uses re-encrypted ciphertext to integrate and collect more than t re-encrypted data for fragment decryption.

[0035] In this embodiment, the present invention employs a dual-threshold key distribution technique to design an encrypted information data sharing method. This avoids the single point of failure problem of proxy servers in traditional proxy re-encryption techniques during the ciphertext forwarding stage. Furthermore, the dual-threshold key distribution technique avoids the single point of failure and key escrow problem of key generation centers in traditional identity-based cryptography during the key distribution stage. The present invention achieves an end-to-end encrypted data encryption method. Even if data is intercepted during transmission, it cannot be decrypted by a third party without the key. The proxy re-encryption technique allows user A's credit data to be directly sent to user B after re-encryption, whereas traditional encryption techniques require user A to decrypt the data to be analyzed and then re-encrypt it before sending it to user B. Compared to traditional encryption techniques, the present invention eliminates a decryption step, reducing server overhead. Moreover, as described in this application, the subsequent ReKeyGen and Dec algorithms are performed after receiving t or more key fragments, avoiding starting operations after receiving only a small amount of data, thus avoiding increased system burden. The system is only activated after receiving a certain number of key fragments.

[0036] Reference Figure 1 In step S1, the Setup algorithm is a system initialization algorithm that outputs random groups G1 and G2 of prime order q, where groups G1 and G2 satisfy a bilinear mapping e. A bilinear mapping e: G1 × G1 → G2 is defined as a group of prime order p. A bilinear mapping e: G1 × G1 → G2 has the following characteristics:

[0037] Bilinear: for all P, Q∈G1 and a, The equation is e(aP,bQ)=e(P,Q) ab Established;

[0038] Non-degeneracy: There exist P, Q∈G such that This represents the unit element of G2.

[0039] Computability: For all P,Q∈G1, there exists a polynomial algorithm to compute e(P,Q).

[0040] Lagrange interpolation is an algorithm used in numerical analysis for interpolation. Given a set of points, it finds a polynomial such that the polynomial equals the known function values ​​at those points. This polynomial is called the interpolation polynomial. The degree (the highest degree of the term) of the polynomial P(x) is less than or equal to n, and it satisfies: P(x... i )=y i Where i = 0, 1, ..., n, the Lagrange interpolation polynomial is defined as: Where L i (x) is a Lagrange polynomial, defined as: Each basic polynomial L i (x) are all polynomials of degree n, which are expressed in x = x i When the value is 1, it is the same as all other x. j When (j≠i), the value is 0.

[0041] Reference Figure 1 In steps S2 and S3, when generating key fragments and re-encryption key fragment vectors, an update request is made after each generation. When executing the update request, the node flag for generating key fragments and re-encryption key fragment vectors is discarded, and new node flags for key fragments and re-encryption key fragment vectors are generated. When the generated key fragments and re-encryption key fragment vectors are received, the old node flag is replaced with the new node flag. When the generated key fragments and re-encryption key fragment vectors are not received and used, the old node flag continues to be used. When replacing the old node flag with the new node flag, the new node flag is sent to the tobacco retail customer who performed the node flag replacement, and the new node flag is recorded and publicized. When a new tobacco retail customer joins, a new node flag is generated and bound to the newly joined tobacco retail customer. When a tobacco retail customer leaves the credit system, the customer's node flag is marked. When the marking time reaches three months and the departing tobacco retail customer has not yet joined, the identity identifier is directly discarded and not redistributed.

[0042] In this embodiment, when encrypting and reencrypting tobacco retail customer credit data, multiple encryption operations increase the risk of data leakage. To avoid this, this application sends an update request every time a tobacco retail customer sends data, marking the node identifier generated by key sharding and reencryption key shard vectors as obsolete. When tobacco retail customers share data normally, the obsolete node identifiers are directly discarded. Therefore, each time a tobacco retail customer uses the system, a new node identity is used, reducing the possibility of data leakage. When the generated key shards and reencryption key shard vectors are not received or used, the old node identifiers continue to be used, avoiding a large waste of node identities. When a tobacco retail customer leaves the credit system, their node identifier is marked. If the marking period reaches three months and the customer has not rejoined, the identifier is directly discarded without reallocation, preventing others from being assigned to previously used node identifiers and causing data leakage. The node identifier is the working address used when generating key sharding and reencryption key shard vectors.

[0043] Reference Figure 1 In step S1, the credit system includes a main system containing credit data of tobacco retail customers and a subsystem for verification. When a tobacco retail customer logs in to the system, the customer connects to the verification system of the subsystem. After the customer's login verification is successful, the subsystem connects to the main system, and the customer can connect to the main system and share information and data.

[0044] In this embodiment, the credit system includes a main system containing credit data of tobacco retail customers and a subsystem for verification. The main system and the subsystem are independent of each other. Therefore, when verification is performed illegally, the operation will only be carried out in the subsystem for verification and will not be mistakenly connected to the main system. This avoids the leakage of data in the main system that stores a large amount of tobacco retail customer information, thus improving the security of this application.

[0045] Reference Figure 1 In step S6, the received data is stored in duplicate using two storage devices for decryption. When storing data on the two storage devices, each re-encrypted data is stored in m data blocks. The two storage devices can communicate and transmit data to each other. When the two storage devices communicate, they compare the number of data blocks corresponding to each re-encrypted data in the two storage devices. When the number of data blocks corresponding to the re-encrypted data in the two storage devices is different, the data block with more data blocks is used instead of the data block with fewer data blocks. When the number of data blocks is the same, the selection is random. After selecting the data block with more data blocks for each re-encrypted data, the data is decrypted.

[0046] In this embodiment, data loss is inevitable during storage. Each re-encrypted data is stored in m data blocks, and both storage devices are used for storage. For example, if the re-encrypted data in one storage device is stored in m data blocks and the re-encrypted data in the other storage device is stored in m-2 data blocks, and two data blocks are lost, then m data blocks are directly used to replace m-2 data blocks. When decrypting the data, the data to be decrypted is more detailed, ensuring that the decrypted data is comprehensive and accurate.

[0047] In this embodiment of the application, when using the Lagrange interpolation method for interpolation calculation, the Lagrange interpolation method can only complete the decryption work when enough data is collected, that is, more than t re-encrypted data can complete the decryption work. If more than t re-encrypted data is not received, no work is performed to reduce the amount of computation. The Lagrange interpolation method is used for threshold secret sharing. A t-order polynomial needs t+1 (x,y) points to be fully recovered. For example, two points determine a straight line, and three points determine a quadratic function, which recovers the complete t-order polynomial. The original secret is placed in P(0), and it can be obtained by substituting x=0. Therefore, the exact Lagrange interpolation method can recover the original secret, rather than an approximation.

[0048] Example 2

[0049] The specific algorithm implementation in this invention includes the following steps: a total of six algorithms, namely Setup, Extract, ReKeyGen, Enc, ReEnc and Dec;

[0050] Setup is the system initialization algorithm. It outputs random groups G1 and G2 of prime order q, satisfying the bilinear mapping e: G1×G1→G2, Z. q Let the set {0,1,…,q-1}, ∈ R This represents randomly selecting elements from a set, where the group generators g, v, v1, v2, w, u1, u2, u3, h1, h2, h3 ∈ G1 are randomly chosen, and the exponents a1, a2, b, α ∈ Z. q ,make Generate master key Output other public parameters

[0051] SKE.Enc and SKE.Dec are the encryption and decryption algorithms for the same symmetric cryptography, respectively.

[0052] Extract is a key generation algorithm; the input user address is ID∈Z. q And the master key msk, select random numbers μ1, μ2, r2, z1, z2, Let r1 = μ1, r = r1 + r2. Calculate... Randomly generate 12 polynomials of degree t, P j (x), j = [1,…,12], let (x), j = [1,…,12] respectively Fragment the output key Where m i For random values ​​that conform to the defined domain.

[0053] ReKeyGen is a re-encryption key generation algorithm that uses fragmented input keys. And the user address ID that needs to be forwarded, calculate Choose random μ'1,μ'2,r'2,z'1,z'2, Let r'1 = μ'1 + μ'2, r' = r'1 + r'2, calculate D'1 = D1·v r′ , make Select random numbers s1, s2, t∈Z q , Let s = s1 + s2, select a random value sk ∈ G2, and calculate... make

[0054] Randomly generate 26 polynomials P of degree t j (x), j = [1,…,26], let P respectively... j (0)=D′1,…,D′6,K′ 1,1 ,K′ 2,1 ,K′ 1,2 ,K′ 2,2 , C0,…,C7,E1,E2, Output the re-encryption key fragment from address ID to address ID' Where m i The identifiers for the n key generation centers that conform to the defined domain.

[0055] Enc is an encryption algorithm; for the plaintext data m and the user address ID, a random value is selected. make Select random value calculate make Output encrypted electronic data

[0056] ReEnc is a re-encryption algorithm; the input address is the encrypted data of address ID. Fragmentation of the re-encrypted key from ID to ID' verify If the validation fails, output a stop character; otherwise, select a random value. calculate Where i = [1, ..., n], select random values. make Select a random value sk'∈G2 and calculate make Output re-encryption fragments Where m i Identifiers for n proxy servers that conform to the defined domain;

[0057] Dec is the decryption algorithm; the input user address ID and key fragments are required. calculate For the original encrypted data calculate run

[0058] For re-encrypted data fragmentation calculate Solve in a similar way as described above. and calculate run

[0059] Example 3

[0060] In the process of generating key fragments and re-encryption key fragments, a special (n,n)-secret sharing method is adopted. Only by receiving all the key fragments or re-encryption key fragments can the key and re-encryption key be recovered. The specific method is as follows:

[0061] Extract. For For each component, taking D1 as an example, it is split into n random pieces such that their product is D1, i.e., D 11 ·D 12 ·…·D 1n =D1, for D2,…,D7,K 1,1 ,K 2,1 ,K 1,2 ,K 2,2 , Repeat this operation, and the remaining steps are the same as described above.

[0062] ReKeyGen. For all key fragments, multiply all fragments belonging to the same component to recover D1,…,D7,K. 1,1 ,K 2,1 ,K 1,2 ,K 2,2 , Perform the same operations as described above during the re-encryption key distribution phase. The 26 components are split into n fragments, and the 26*n fragments are sent to proxy servers 1-n respectively (each proxy server receives 26*1 fragments);

[0063] ReEnc. Calculation The remaining steps are the same as described above;

[0064] Dec. For all key fragments, multiply all fragments belonging to the same component to recover D1,…,D7,K. 1,1 ,K 2,1 ,K 1,2 ,K 2,2 ,

[0065] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. The units and algorithm steps of the various examples described in the embodiments can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0066] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0067] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0068] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for securely sharing tobacco retail customer credit data based on proxy re-encryption, characterized in that: Includes the following steps: Step S1: Establish a credit system. Tobacco retail customers log in to the credit system using password verification. Step S2: After logging into the credit system, initialization is performed. During data initialization, the Setup algorithm is executed to generate initial system parameters. Step S3: Call the Extract algorithm to generate n key fragments. Each key fragment consists of a vector of 12 group elements. Send the data containing the key fragments. In step S4, during the data transmission of key fragments, after the re-encryption key system receives more than t key fragments, it receives all key fragments, executes the ReKeyGen algorithm, and generates n re-encryption key fragment vectors with 26 group elements. Step S5: After the re-encryption key system generates re-encryption key fragments, it executes the Enc algorithm, inputs the address of the data receiver, outputs encrypted data, and sends it to n proxy servers respectively. Step S6: n proxy servers receive the encrypted data, execute the ReEnc algorithm, and each proxy server outputs a re-encrypted data fragment. Step S7: After receiving more than t key fragments, the receiver waits to receive all the key fragments, executes the Dec algorithm for decryption, and uses re-encrypted ciphertext to integrate and collect more than t re-encrypted data for fragment decryption. In step S1, the credit system includes a main system containing credit data of tobacco retail customers and a subsystem for verification. When a tobacco retail customer logs in to the system, the customer is connected to the verification system of the subsystem. After the customer's login verification is successful, the subsystem is connected to the main system, and the customer can access the main system and share information and data. In step S6, when collecting more than t re-encrypted data for fragment decryption, the Lagrange interpolation method is used to perform interpolation combination of more than t re-encrypted data fragments. When the number of keys is more than t, the re-encrypted data is decrypted. When the number of keys is t or less, no decryption is performed. In steps S2 and S3, when generating key fragments and re-encryption key fragment vectors, an update request is made after each generation. When executing the update request, the node flag for generating key fragments and re-encryption key fragment vectors is discarded, and new node flags for key fragments and re-encryption key fragment vectors are generated. When the generated key fragments and re-encryption key fragment vectors are received, the new node flags replace the old node flags. When the generated key fragments and re-encryption key fragment vectors are not received and used, the old node flags continue to be used. When replacing an old node marker with a new one, the new node marker is sent to the tobacco retail customer who is replacing the node marker, and the new node marker is recorded and publicized. When a new tobacco retail customer joins, a new node marker is generated and bound to the newly joined tobacco retail customer. When a tobacco retail customer leaves the credit system, the customer's node marker is marked. When the marking period reaches three months and the leaving tobacco retail customer has not yet joined, the node marker is directly discarded and not redistributed.

2. The method for securely sharing tobacco retail customer credit data based on proxy re-encryption according to claim 1, characterized in that: In step S1, the Setup algorithm is a system initialization algorithm that outputs random groups G1 and G2 of prime order q, and groups G1 and G2 satisfy the bilinear mapping e.

3. The method for securely sharing tobacco retail customer credit data based on proxy re-encryption according to claim 1, characterized in that: In step S6, the received data is decrypted using two storage devices for dual storage. When storing data on the two storage devices, each re-encrypted data is stored in m data blocks. The two storage devices can communicate and transmit data to each other.

4. The method for securely sharing tobacco retail customer credit data based on proxy re-encryption according to claim 1, characterized in that: When two storage devices communicate, the number of data blocks corresponding to each re-encrypted data in the two storage devices is compared. When the number of data blocks corresponding to the re-encrypted data in the two storage devices is different, the data block with more data blocks is used instead of the data block with fewer data blocks. When the number of data blocks is the same, the selection is random. After selecting the data block with more data blocks for each re-encrypted data, the data is decrypted.

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