A fast adaptive security attribute encryption method and system

Abstract

The present invention relates to data encryption technology and discloses a fast and adaptive security attribute encryption method, comprising: initialization of a key generation center, calculation of a policy-hidden ciphertext by a data owner, and uploading it to a cloud server; a data user sends an identity identifier and attribute set to the key generation center for verification, which generates a user key and sends it to the data user; the data user calculates an outsourced key; when the user key parameter quantity is less than a preset parameter quantity threshold, the data user calculates a first plaintext message based on the user key and the policy-hidden ciphertext; when the user key parameter quantity is greater than or equal to the preset parameter quantity threshold, the data user calculates a partial decrypted ciphertext and sends the partial decrypted ciphertext to the data user; the data user decrypts the partial decrypted ciphertext to obtain a second plaintext message. The present invention also proposes a fast and adaptive security attribute encryption system. The present invention can improve the efficiency of security attribute encryption and reduce computational costs.

Description

Technical Field

[0001] The present invention belongs to the technical field of data encryption, and in particular relates to a fast adaptive security attribute encryption method and system. Background Art

[0002] With the deep integration of the Internet of Things (IoT) and cloud computing technologies, the flow and sharing of data generated by massive terminal devices in open networks has become the norm. However, achieving the unification of data privacy protection and efficient access control in complex and ever-changing network environments has become a core challenge in the field of information security. Ciphertext Policy Attribute-Based Encryption (CP-ABE) technology provides a theoretical foundation for fine-grained access control by dynamically binding data decryption permissions to preset policies. However, the inherent contradiction between security and lightweight implementation has never been fully resolved. While current research continues to make breakthroughs in these two major areas, it is difficult to meet the actual situation of limited computing power in IoT devices due to the fragmentation of technical paths and the limitations of scenario adaptation.

[0003] At the level of complete security, existing schemes strive to break away from the idealized assumptions of the random oracle model (ROM) and instead construct adaptive security schemes under the standard model. For example, the ABE scheme, based on dual-system cryptography, is constructed using a composite-order bilinear elliptic curve group. Due to the orthogonality of the subgroups of this group, this type of scheme can mask the main elements using different subgroup elements and resolve the masked values ​​during the decryption phase, preventing the adversary from obtaining valid information through adaptive chosen ciphertext attacks (CCAs), thereby achieving adaptive security under the standard model. However, this type of scheme comes at the expense of computational efficiency—for composite-order groups and prime-order groups with the same number of security bits, the computational efficiency of the composite-order group is far lower than that of the prime-order group. This makes the scheme that meets the adaptive security requirements less efficient and difficult to meet the computing power limitations of IoT edge devices.

[0004] To meet the demand for lightweight solutions, researchers have attempted to reduce the resource consumption of CP-ABE schemes through algorithm optimization and architectural reconstruction. Offline / online encryption separation technology is a typical example: in the offline stage, complex operations such as bilinear pairings and exponential operations are pre-calculated, and the intermediate results are stored locally; in the online stage, only the final ciphertext needs to be generated in combination with real-time properties, which significantly reduces encryption latency. In addition, there is also the use of outsourced decryption technology to transfer core computing tasks to the cloud or edge server, and users only need to submit part of the decryption parameters and verify the correctness of the returned results. However, the above-mentioned lightweight solutions often require the introduction of additional trust assumptions, resulting in lower privacy. In addition, lightweight solutions are essentially a transfer of computing tasks, which does not fundamentally improve the computational efficiency of the solution. The computational efficiency is low and will increase additional communication costs. Summary of the Invention

[0005] The present invention provides a fast adaptive security attribute encryption method and system, which can improve the security attribute encryption efficiency and reduce the calculation cost.

[0006] To achieve the above objectives, the present invention provides a fast adaptive security attribute encryption method, comprising:

[0007] The key generation center initializes and generates system public parameters and master keys;

[0008] The data owner formulates an encryption policy for local data and generates a policy matrix. The policy hidden ciphertext is calculated based on the policy matrix and uploaded to the cloud server.

[0009] The data user sends the identity and attribute set to the key generation center for verification. After the verification is passed, the key generation center generates the user key of the data user and sends it to the data user;

[0010] After receiving the user key, the data user calculates the outsourcing key based on the user key;

[0011] When the user key parameter amount is less than the preset parameter amount threshold, the data user sends a policy-hidden ciphertext request to the cloud server. The cloud server responds to the request and sends the policy-hidden ciphertext to the data user. The data user calculates the first plaintext message based on the user key and the policy-hidden ciphertext.

[0012] When the user key parameter quantity is greater than or equal to the preset parameter quantity threshold, the data user sends the outsourced key to the edge server, and the edge server requests the policy-hidden ciphertext from the cloud server. After receiving the policy-hidden ciphertext, the edge server calculates the partial decrypted ciphertext and sends the partial decrypted ciphertext to the data user; the data user decrypts the partial decrypted ciphertext to obtain the second plaintext message.

[0013] Optionally, the key generation center initializes and generates system public parameters and a master key, including:

[0014] The key generation center selects an elliptic curve based on the security parameters and constructs a bilinear elliptic curve group of a preset order based on the elliptic curve;

[0015] The key generation center arbitrarily selects a first curve group and a second curve group from the bilinear elliptic curve group;

[0016] Constructing a real matrix according to the generator of the first curve group, the generator of the second curve, and random elements on an integer set of a preset length;

[0017] The system public parameters and master key are generated using real number matrices.

[0018] Optionally, the data owner formulates an encryption policy for local data and generates a policy matrix, including:

[0019] The data owner converts the local data into attribute pairs, where the attribute pairs include attribute names and attribute values;

[0020] The attribute pairs are converted into Boolean expressions and a linear secret sharing matrix is ​​constructed to obtain the policy matrix.

[0021] Optionally, calculating the policy-hidden ciphertext according to the policy matrix includes:

[0022] The data owner randomly selects elements from an integer set of a preset length to construct a first key auxiliary matrix and randomly selects a first public vector from a column space vector of the first public matrix;

[0023] The ciphertext is hidden by using the first key auxiliary matrix and the first public vector calculation strategy.

[0024] Optionally, the key generation center generates a user key for a data user, including:

[0025] The key generation center randomly selects a key auxiliary vector from the second key auxiliary matrix and randomly selects a second public vector from the column space of the second public matrix including the attribute set;

[0026] The key generation center calculates the user key based on the key auxiliary vector and the second public vector.

[0027] Optionally, the data user calculates the first plaintext message based on the user key and the policy-hidden ciphertext, including:

[0028] The data user requests the cloud server to hide the ciphertext through the policy;

[0029] The cloud server responds to the request and returns the policy-hidden ciphertext to the data user;

[0030] The data user calculates the minimum authorized attribute set based on the policy matrix and the attribute name set in the attribute pair;

[0031] A first plaintext message is calculated based on the policy-hidden ciphertext, the user key, and the minimum authorized attribute set.

[0032] Optionally, after receiving the policy hidden ciphertext, the edge server calculates a partial decrypted ciphertext, including:

[0033] Use the following formula to calculate the partial decryption ciphertext

[0034]

[0035] in, is the set of minimum authorized attribute sets, ω x is an encrypted real number, e is a bilinear map, is the user identity key parameter, is the user identity key masking parameter, C' is the ciphertext composition parameter, Parameters related to user attribute keys.

[0036] In order to solve the above problems, the present invention also provides a system for a fast adaptive security attribute encryption method, which includes: a key generation center, a cloud server, a data owner, a data user and an edge server.

[0037] Optionally, the cloud server receives the policy-hidden ciphertext generated by the data owner, responds to the policy-hidden ciphertext request from the data user, and sends the policy-hidden ciphertext to the data user.

[0038] Optionally, the data user sends the outsourced key to the edge server, the edge server requests the policy hidden ciphertext from the cloud server, and after receiving the policy hidden ciphertext, the edge server calculates the partial decrypted ciphertext and sends the partial decrypted ciphertext to the data user, and the data user decrypts the partial decrypted ciphertext.

[0039] The present invention can realize the security foundation under the standard model by initializing and generating system public parameters and master keys through the key generation center. In addition, the data owner formulates an encryption strategy for local data and generates a policy matrix, calculates the policy hidden ciphertext according to the policy matrix and uploads the policy hidden ciphertext to the cloud server, which can reduce the complexity of local execution policy formulation and partial encryption, and ensure the policy privacy of the encryption strategy. In addition, after receiving the user key, the data user calculates the outsourced key according to the user key. The outsourced key can reduce the risk of sensitive information leakage. In addition, the outsourced key can also be used to calculate high-overhead decryption tasks in the edge server, reducing computing costs and improving computing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of a process flow of a fast adaptive security attribute encryption method provided by one embodiment of the present invention;

[0041] Figure 2 A system initialization flow chart of a fast adaptive security attribute encryption method provided by an embodiment of the present invention;

[0042] Figure 3 A data encryption flow chart of a fast adaptive security attribute encryption method provided by an embodiment of the present invention;

[0043] Figure 4 A flowchart of user key generation in a fast adaptive security attribute encryption method provided by an embodiment of the present invention;

[0044] Figure 5 A flowchart of outsourced key generation for a fast adaptive security attribute encryption method provided by an embodiment of the present invention;

[0045] Figure 6 A flowchart of data user decryption of a fast adaptive security attribute encryption method provided by an embodiment of the present invention;

[0046] Figure 7 A flowchart of the outsourced decryption part of the fast adaptive security attribute encryption method provided by one embodiment of the present invention;

[0047] Figure 8 A flowchart of the data user outsourcing portion decryption of the fast adaptive security attribute encryption method provided by one embodiment of the present invention;

[0048] Figure 9 A system diagram of a fast adaptive security attribute encryption method provided by one embodiment of the present invention.

[0049] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0050] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] The embodiment of the present application provides a fast adaptive security attribute encryption method. The execution subject of the fast adaptive security attribute encryption method includes but is not limited to at least one of the electronic devices such as the server, the terminal, etc. that can be configured to execute the method provided by the embodiment of the present application. In other words, the fast adaptive security attribute encryption method can be executed by software or hardware installed on the terminal device or the server device, and the software can be a blockchain platform. The server includes but is not limited to: a single server, a server cluster, a cloud server or a cloud server cluster, etc. The server can be an independent server, or it can be a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms.

[0052] Reference Figure 1 FIG. 1 is a flow chart of a fast adaptive security attribute encryption method according to an embodiment of the present invention. In this embodiment, the fast adaptive security attribute encryption method includes:

[0053] S1. The key generation center initializes and generates system public parameters and master keys.

[0054] In the embodiment of the present invention, a Key Generation Center (KGC) refers to a trusted third-party entity or service in a cryptography and security system, whose main responsibilities are to generate, manage and distribute cryptographic keys and ensure cryptographic security.

[0055] As an embodiment of the present invention, the key generation center initializes and generates system public parameters and a master key, including:

[0056] The key generation center selects an elliptic curve based on the security parameters and constructs a bilinear elliptic curve group of a preset order based on the elliptic curve;

[0057] The key generation center arbitrarily selects a first curve group and a second curve group from the bilinear elliptic curve group;

[0058] Constructing a real matrix according to the generator of the first curve group, the generator of the second curve, and random elements on an integer set of a preset length;

[0059] The system public parameters and master key are generated using real number matrices.

[0060] Exemplarily, the key generation center initializes and generates system public parameters and a master key, and the following implementation steps may be used:

[0061] Step 101: The key generation center generates a key based on security parameter 1. λ To select an elliptic curve and construct a bilinear elliptic curve group of order p on it, the bilinear elliptic curve group can be described as Among them, G1, G2, G T is a group of order p, e is a bilinear map G1×G2→G T .

[0062] Step 102: The key generation center randomly selects the generators g1 and g2 of groups G1 and G2, and selects them from the set of integers from 1 to p. Uniformly randomly select elements from the above matrix to construct matrices A1, K, B, W, W0, W1, where A1 is the first public matrix, K is the first key auxiliary matrix, B is the second key auxiliary matrix, W is the first security matrix, W0 is the second security matrix, and W1 is the third security matrix. A1 and K are 3×1 matrices, B is a 2×1 matrix, and W, W0, and W1 are 3×2 matrices. For simplicity, g1 will be X Expressed as [X]1, g2 X It is expressed as [X]2, where X is any matrix composed of real numbers.

[0063] Step 103: Key Generation Center Calculation and in Satisfy the following constraints, is the second common matrix:

[0064] ①

[0065] ②

[0066] Where I is the identity matrix and 0 is the zero matrix.

[0067] Step 104: The key generation center calculates and publishes the system public parameter PK as:

[0068]

[0069] The master key MK is calculated as:

[0070]

[0071] In an embodiment of the present invention, system public parameters refer to a set of data generated and publicly distributed by the key generation center during the system establishment phase. Any participant (user, encryption party, verification party, etc.) can freely obtain system public parameters, which mainly provide necessary algorithm parameters for public operations such as encryption, verification, and key requests within the system.

[0072] In the embodiment of the present invention, the master key refers to the core key generated by the key generation center during the system establishment phase and stored in strict confidentiality, and is the highest key for system security.

[0073] S2. The data owner formulates an encryption policy for local data and generates a policy matrix. The policy hidden ciphertext is calculated based on the policy matrix and uploaded to the cloud server.

[0074] In the embodiment of the present invention, the data owner refers to the device or entity that stores the data.

[0075] In an embodiment of the present invention, the encryption policy is expressed as a Boolean expression consisting of attribute pairs, each attribute pair consisting of an attribute name and a corresponding attribute value, for example, "(occupation: psychiatrist) OR (ID: 153759)", where "occupation" and "ID" are attribute names, and "psychiatrist" and "153759" are corresponding attribute values.

[0076] In the embodiment of the present invention, the encryption policy may determine which data users may access their encrypted data.

[0077] As an embodiment of the present invention, the data owner formulates an encryption policy for local data and generates a policy matrix, including:

[0078] The data owner converts the local data into attribute pairs, where the attribute pairs include attribute names and attribute values;

[0079] The attribute pairs are converted into Boolean expressions and a linear secret sharing matrix is ​​constructed to obtain the policy matrix.

[0080] For example, the data owner formulates an encryption policy for local data and generates a policy matrix, which can be implemented using the following steps:

[0081] The data owner converts the Boolean expression form of the policy into a linear secret sharing matrix form, called the policy matrix Where P is a matrix with l rows and n columns, l is the number of attribute pairs in the policy, and n is related to the nesting complexity of the policy; ρ is the set of mapping relationships that maps a row of the matrix P to the attribute name space, and v is the set of attribute values ​​corresponding to the attribute name.

[0082] As an embodiment of the present invention, calculating a policy-hidden ciphertext according to a policy matrix includes:

[0083] The data owner randomly selects elements from an integer set of a preset length to construct a first key auxiliary matrix and randomly selects a first public vector from a column space vector of the first public matrix;

[0084] The ciphertext is hidden by using the first key auxiliary matrix and the first public vector calculation strategy.

[0085] In an embodiment of the present invention, policy hiding ciphertext refers to a security enhancement technology whose core purpose is to hide the structural information of the access policy (Access Policy) to prevent attackers from inferring sensitive attribute information or policy logic from the ciphertext, thereby significantly improving the privacy protection strength of the system.

[0086] For example, the following implementation steps may be used to calculate the policy hidden ciphertext according to the policy matrix:

[0087] Data owner from Randomly select elements from the matrix K' to construct a 3×(n-1) matrix, and randomly select vector a from the column vector space of A1. Then calculate the strategy to hide the ciphertext in m is the plaintext message, v ρ(x) is the attribute value corresponding to the x-th attribute pair in the set v.

[0088] S3. The data user sends the identity and attribute set to the key generation center for verification. After the verification is passed, the key generation center generates the user key of the data user and sends it to the data user.

[0089] In the embodiment of the present invention, a data user refers to an entity that obtains access rights after identity authentication and can use a key to decrypt encrypted data or perform specific operations.

[0090] As an embodiment of the present invention, a key generation center generates a user key for a data user, including:

[0091] The key generation center randomly selects a key auxiliary vector from the second key auxiliary matrix and randomly selects a second public vector from the column space of the second public matrix including the attribute set;

[0092] The key generation center calculates the user key based on the key auxiliary vector and the second public vector.

[0093] For example, a data user sends an identity identifier and attribute set to a key generation center for verification, and the following implementation steps may be used:

[0094] Step 301: The data user identifies his / her identity U ID Sent to the key generation center.

[0095] Step 302: The key generation center verifies whether the identifier has been registered. If not, the process proceeds to the next step; if already registered, the process terminates.

[0096] Step 303: Data users collect their own attributes Sent to the key generation center, where S N Is a set of attribute names, S V Is the corresponding attribute value set.

[0097] Step 304: The key generation center verifies whether the attribute set is legal. If so, the process proceeds to the next step; otherwise, the process terminates.

[0098] Furthermore, after the identity identifier and attribute set are verified to be legal by the key generation center, the key generation center generates a user key for the data user, which can be implemented using the following steps:

[0099] The key generation center randomly selects a vector b from the column vector space of B, The column vector space of Each attribute in randomly selects a vector Then calculate the key Where K=[b]2, K'=[K+Wb]2, s i It's S V The corresponding attribute value in .

[0100] S4. After receiving the user key, the data user calculates the outsourcing key based on the user key.

[0101] In an embodiment of the present invention, outsourcing keys is a security mechanism used in encryption systems to reduce local computing burden and improve efficiency. Its core idea is to entrust complex computing tasks in the key generation, management or decryption process to a third-party service, while ensuring the security of the outsourcing process through cryptographic technology.

[0102] For example, after receiving the user key, the data user calculates the outsourcing key based on the user key by using the following implementation steps:

[0103] Step 401: Data user Randomly select element t from

[0104] Step 402: Data users use SK ID Calculating outsourced keys in

[0105] S5. When the user key parameter amount is less than the preset parameter amount threshold, the data user sends a policy-hidden ciphertext request to the cloud server. After responding to the request, the cloud server sends the policy-hidden ciphertext to the data user. The data user calculates the first plaintext message based on the user key and the policy-hidden ciphertext.

[0106] As an embodiment of the present invention, a data user calculates a first plaintext message based on a user key and a policy-hidden ciphertext, including:

[0107] The data user requests the cloud server to hide the ciphertext through the policy;

[0108] The cloud server responds to the request and returns the policy-hidden ciphertext to the data user;

[0109] The data user calculates the minimum authorized attribute set based on the policy matrix and the attribute name set in the attribute pair;

[0110] A first plaintext message is calculated based on the policy-hidden ciphertext, the user key, and the minimum authorized attribute set.

[0111] Exemplarily, when the user key parameter amount is less than a preset parameter amount threshold, the data user sends a policy-hidden ciphertext request to the cloud server. The cloud server responds to the request and sends the policy-hidden ciphertext to the data user. The data user calculates the first plaintext message based on the user key and the policy-hidden ciphertext. The following implementation steps may be used:

[0112] Step 501: The data user requests the cloud server to hide the ciphertext with a policy

[0113] Step 502: The cloud server sends the policy hidden ciphertext to the data user.

[0114] Step 503: The data user first and S N Compute the minimum set of authorized attributes Then based on the key SK ID and Perform the following calculations:

[0115]

[0116] Among them, ω x satisfy The attribute set of the data user satisfy When the requirement is met, the calculation result is the plaintext information m; when Does not satisfy the strategy matrix When the requirement is met, the calculation result is a meaningless group element.

[0117] S6. When the user key parameter quantity is greater than or equal to the preset parameter quantity threshold, the data user sends the outsourced key to the edge server, and the edge server requests the policy-hidden ciphertext from the cloud server. After receiving the policy-hidden ciphertext, the edge server calculates the partial decrypted ciphertext and sends the partial decrypted ciphertext to the data user; the data user decrypts the partial decrypted ciphertext to obtain the second plaintext message.

[0118] Exemplarily, when the user key parameter quantity is greater than or equal to a preset parameter quantity threshold, the data user sends the outsourced key to the edge server, the edge server requests the policy-hidden ciphertext from the cloud server, and after receiving the policy-hidden ciphertext, the edge server calculates a partial decrypted ciphertext and sends the partial decrypted ciphertext to the data user; the data user decrypts the partial decrypted ciphertext to obtain a second plaintext message, and the following implementation steps may be used:

[0119] Step 601: The data user uses his outsourced key OutSK ID Sent to the edge server.

[0120] Step 602: The edge server requests the policy hidden ciphertext from the cloud server

[0121] Step 603: The cloud server sends the policy hidden ciphertext to the edge server.

[0122] Step 604: The edge server calculates the partially decrypted ciphertext

[0123] in, is the set of minimum authorized attribute sets, ω x is an encrypted real number, e is a bilinear map, is the user identity key parameter, is the user identity key masking parameter, C' is the ciphertext composition parameter, Parameters related to user attribute keys.

[0124] Among them, ω x satisfy P x refers to the strategy matrix The x-th row vector of .

[0125] Step 605: The edge server partially decrypts the ciphertext Sent to data users.

[0126] Step 606: Data User Calculation When the attribute set of the data user satisfy When the requirement is met, the calculation result is the plaintext information m; when Does not satisfy the strategy matrix When the requirement is met, the calculation result is a meaningless group element.

[0127] In the embodiment of the present invention, They are the three components of the outsourcing key, which are calculated from the user key. Related to user identity, is the masked portion of the key. It is the part of the key related to the user attributes, and C' is a part of the ciphertext, which is mainly used to eliminate the masked value of the part of the ciphertext containing plaintext information.

[0128] The present invention can realize the security foundation under the standard model by initializing and generating system public parameters and master keys through the key generation center. In addition, the data owner formulates an encryption strategy for local data and generates a policy matrix, calculates the policy hidden ciphertext according to the policy matrix and uploads the policy hidden ciphertext to the cloud server, which can reduce the complexity of local execution policy formulation and partial encryption, and ensure the policy privacy of the encryption strategy. In addition, after receiving the user key, the data user calculates the outsourced key according to the user key. The outsourced key can reduce the risk of sensitive information leakage. In addition, the outsourced key can also be used to calculate high-overhead decryption tasks in the edge server, reducing computing costs and improving computing efficiency.

[0129] like Figure 2 FIG. 1 is a flow chart showing system initialization of a fast adaptive security attribute encryption method according to an embodiment of the present invention.

[0130] like Figure 3 FIG. 1 is a data encryption flow chart of a fast adaptive security attribute encryption method provided by an embodiment of the present invention.

[0131] like Figure 4 FIG. 1 is a flowchart of a user key generation method for a fast adaptive security attribute encryption method provided by an embodiment of the present invention.

[0132] like Figure 5 FIG. 1 is a flowchart of outsourced key generation in a fast adaptive security attribute encryption method provided by an embodiment of the present invention.

[0133] like Figure 6 FIG. 1 is a flowchart of data user decryption of a fast adaptive security attribute encryption method provided by an embodiment of the present invention.

[0134] like Figure 7 FIG. 1 is a flowchart of the outsourced decryption process of the fast adaptive security attribute encryption method provided by an embodiment of the present invention.

[0135] like Figure 8 FIG. 1 is a flowchart of the data user outsourcing portion decryption of the fast adaptive security attribute encryption method provided by an embodiment of the present invention.

[0136] like Figure 9 FIG. 1 is a system diagram of a fast adaptive security attribute encryption method provided by an embodiment of the present invention.

[0137] As an embodiment of the present invention, the system includes: a key generation center, a cloud server, a data owner, a data user, and an edge server.

[0138] Furthermore, the cloud server receives the policy-hidden ciphertext generated by the data owner, responds to the policy-hidden ciphertext request of the data user, and sends the policy-hidden ciphertext to the data user.

[0139] Furthermore, the data user sends the outsourced key to the edge server, the edge server requests the policy hidden ciphertext from the cloud server, and after receiving the policy hidden ciphertext, the edge server calculates the partial decrypted ciphertext and sends the partial decrypted ciphertext to the data user, and the data user decrypts the partial decrypted ciphertext.

[0140] It should be understood that the embodiment is for illustration only and the scope of the patent application is not limited to this structure.

[0141] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0142] Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalents of the claims are intended to be embraced therein. Any reference to a figure in a claim should not be construed as limiting the claim to which it relates.

[0143] Blockchain, as used in this article, refers to a novel application model for computer technologies such as distributed data storage, peer-to-peer transmission, consensus mechanisms, and encryption algorithms. Blockchain is essentially a decentralized database, a series of data blocks generated using cryptographic methods. Each block contains information about a batch of online transactions, used to verify the validity of this information (to prevent counterfeiting) and generate the next block. Blockchain can include the underlying blockchain platform, the platform product service layer, and the application service layer.

[0144] The embodiments of the present application can acquire and process relevant data based on artificial intelligence technology. Artificial Intelligence (AI) is the theory, method, technology, and application system that uses digital computers or machines controlled by digital computers to simulate, extend, and expand human intelligence, perceive the environment, acquire knowledge, and use knowledge to achieve optimal results.

[0145] Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or devices recited in a system claim may also be implemented by a single unit or device through software or hardware. Terms such as "first" and "second" are used to indicate names and do not imply any particular order.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A fast adaptive security attribute encryption method, characterized in that: The method comprises: The key generation center initializes and generates system public parameters and master keys; The data owner formulates an encryption policy for local data and generates a policy matrix. The policy hidden ciphertext is calculated based on the policy matrix and uploaded to the cloud server. The data user sends the identity and attribute set to the key generation center for verification. After the verification is passed, the key generation center generates the user key of the data user and sends it to the data user; After receiving the user key, the data user calculates the outsourcing key based on the user key; When the user key parameter amount is less than the preset parameter amount threshold, the data user sends a policy-hidden ciphertext request to the cloud server. The cloud server responds to the request and sends the policy-hidden ciphertext to the data user. The data user calculates the first plaintext message based on the user key and the policy-hidden ciphertext. When the user key parameter quantity is greater than or equal to the preset parameter quantity threshold, the data user sends the outsourced key to the edge server, and the edge server requests the policy-hidden ciphertext from the cloud server. After receiving the policy-hidden ciphertext, the edge server calculates the partial decrypted ciphertext and sends the partial decrypted ciphertext to the data user; the data user decrypts the partial decrypted ciphertext to obtain the second plaintext message.

2. The fast adaptive security attribute encryption method according to claim 1, characterized in that: The key generation center initializes and generates system public parameters and master keys, including: The key generation center selects an elliptic curve based on the security parameters and constructs a bilinear elliptic curve group of a preset order based on the elliptic curve; The key generation center arbitrarily selects a first curve group and a second curve group from the bilinear elliptic curve group; Constructing a real matrix according to the generator of the first curve group, the generator of the second curve, and random elements on an integer set of a preset length; The system public parameters and master key are generated using real number matrices.

3. The fast adaptive security attribute encryption method according to claim 1, wherein: The data owner formulates an encryption policy for local data and generates a policy matrix, including: The data owner converts the local data into attribute pairs, where the attribute pairs include attribute names and attribute values; The attribute pairs are converted into Boolean expressions and a linear secret sharing matrix is ​​constructed to obtain the policy matrix.

4. The fast adaptive security attribute encryption method according to claim 1, wherein: The step of calculating the policy hidden ciphertext according to the policy matrix includes: The data owner randomly selects elements from an integer set of a preset length to construct a first key auxiliary matrix and randomly selects a first public vector from a column space vector of the first public matrix; The ciphertext is hidden by using the first key auxiliary matrix and the first public vector calculation strategy.

5. The fast adaptive security attribute encryption method according to claim 1, wherein: The key generation center generates a user key for a data user, including: The key generation center randomly selects a key auxiliary vector from the second key auxiliary matrix and randomly selects a second public vector from the column space of the second public matrix including the attribute set; The key generation center calculates the user key based on the key auxiliary vector and the second public vector.

6. The fast adaptive security attribute encryption method according to claim 2, wherein: The data user calculates a first plaintext message based on the user key and the policy-hidden ciphertext, including: The data user requests the cloud server to hide the ciphertext through the policy; The cloud server responds to the request and returns the policy-hidden ciphertext to the data user; The data user calculates the minimum authorized attribute set based on the policy matrix and the attribute name set in the attribute pair; A first plaintext message is calculated based on the policy-hidden ciphertext, the user key, and the minimum authorized attribute set.

7. The fast adaptive security attribute encryption method according to claim 1, wherein: After receiving the policy hidden ciphertext, the edge server calculates a partial decrypted ciphertext, including: Use the following formula to calculate the partial decryption ciphertext in, is the set of minimum authorized attribute sets, ω x is an encrypted real number, e is a bilinear map, is the user identity key parameter, is the user identity key masking parameter, C' is the ciphertext component, Parameters related to user attribute keys.

8. A system for implementing the fast adaptive security attribute encryption method according to any one of claims 1 to 7, the system comprising: Key generation center, cloud server, data owner, data user and edge server.

9. The system of the fast adaptive security attribute encryption method according to claim 8, comprising: The cloud server receives the policy hidden ciphertext generated by the data owner, responds to the policy hidden ciphertext request of the data user, and sends the policy hidden ciphertext to the data user.

10. The system of the fast adaptive security attribute encryption method according to claim 8, comprising: The data user sends the outsourced key to the edge server, the edge server requests the policy hidden ciphertext from the cloud server, and after receiving the policy hidden ciphertext, the edge server calculates the partial decrypted ciphertext and sends the partial decrypted ciphertext to the data user, and the data user decrypts the partial decrypted ciphertext.

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