An access control authorization method based on multi-level security and secret sharing

Abstract

The present invention discloses an access control authorization method based on multi-level security and secret sharing. The authorization steps of the method include: first, the system divides the security level of resources, generates subkeys, and randomly transfers the subkeys and matching attributes to trusted management points for storage and preservation; second, the user requests an attribute certificate from the system to determine the security level; then, when the user requests a resource, the system verifies the attribute certificate and user signature and other information. If the verification is successful, the subkey is returned; if the verification fails, it returns null; finally, the system compares the user request with the resource permission table. If they are consistent, the resource is returned and authorized; otherwise, it is rejected. The present invention considers the scope of resources that users can legally access from the perspective of attributes, realizes multi-level security of user access, reduces the possibility of resource leakage, and ensures the confidentiality of system resources.

Description

Technical Field

[0001] The invention belongs to the field of computer software development, and particularly designs an access authorization method of attribute grading and secret sharing. Background Art

[0002] With the continuous emergence of some new technologies, especially the development of cloud computing, data security issues have become increasingly complex. Virtualization technology and complex network environments have also brought about security issues for services and resources. Data storage and access methods have undergone major changes. In addition, the form of network security threats is also constantly changing. Hacker attacks are becoming more and more advanced and difficult to detect. These threats have posed new challenges to access control.

[0003] Currently, in diverse environments, access control faces the following issues: 1. Risk of resource leakage: Resources are scattered across cloud environments and may be leaked due to improper security settings, authentication and authorization issues, configuration errors, software vulnerabilities, and other reasons. 2. Service security: The lack of trust assessment in the access control model will lead to illegal access by malicious users, which will damage the confidentiality of resources. Although there are currently various solutions to introduce trust mechanisms, they lack strong support in terms of computing efficiency, reliability, and feasibility. 3. User privacy protection: The access control model controls user access behavior, but lacks security considerations from the user's perspective. User requests for resources often involve some personal privacy information, which is often private. Therefore, when ensuring that users have legal access to resources, more attention should be paid to the security of data management.

[0004] In summary, how to ensure the security of system resources and prevent illegal access to system resources has become an urgent problem to be solved in this field. Summary of the Invention

[0005] In order to solve the technical problems mentioned in the above background technology, the present invention proposes an access control authorization method based on multi-level security and secret sharing.

[0006] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0007] 1. An access control authorization method based on domain management and mirror role mapping, characterized by comprising the following steps:

[0008] (1) During the system initialization phase, the user's resource operation permissions are restricted and managed based on the Shamir secret sharing scheme. First, the resources are divided into security levels, and a secret S is preset for each resource. The Shamir secret sharing scheme is used to divide S into n unrelated parts of information. Each part of information is a subkey. The system administrator distributes each subkey and its matching attributes to each trusted management point for storage.

[0009] (2) The user sends an attribute certificate request to the attribute authority AA. The AA first queries the attribute certificate registration center ACR to see if there is a user application record. If so, it extracts the ACRL from the certificate library ACRL and returns it to the attribute authority AA. Otherwise, the attributes are sent to the attribute classification point ACP. The ACP divides the user attributes and the classification attributes, performs security classification on the user based on the classification attributes, and returns the result to the AA. The AA then sends the attribute certificate back to the user.

[0010] (3) The user sends an authorization request Req to the request execution point QEP;

[0011] (4) QEP verifies the AA signature and other information. If it passes, it sends the attribute to the trusted management point to request the subkey. The trusted management point verifies the attribute and returns the subkey if it meets the requirements. Otherwise, it returns nothing.

[0012] (5) QEP sends the request and subkey set to the policy management point PAP. PAP compares the request with the resource permission table. If it matches, it returns the resource and authorizes it. Otherwise, it rejects it.

[0013] 2. Furthermore, in step (1), the specific process of generating the subkey is as follows:

[0014] (101) First, divide the resource Object into security levels and read the secret as S r , the secret is stored by the policy administration point PAP;

[0015] (102) Take large prime numbers P for read and write permissions respectively r ,Here we choose a larger prime number to ensure non-repeatability;

[0016] (103) Determine the read threshold RT r and write threshold WT r ,The read and write threshold of each resource is determined by the resource security level, and the high security level threshold is higher than the low security level threshold;

[0017] (104) Determine the number of key holders n. For read and write operations, in order to ensure the confidentiality principle of BLP, we stipulate that any resource must ensure that the number of key holders is different, and the number of key holders of each resource must be greater than or equal to max(RT, Wt);

[0018] (105) Generate the polynomial f(x) as follows:

[0019] f(x)=S r +a1x+a2x 2 +a3x 3 +…+a t-1 xt-1 (1-1)

[0020] Among them, S r Indicates resource read secret, a1, a2, a3, ..., a t-1 Indicates that from 1-P r Randomly pick t-1 numbers from the finite field;

[0021] (106) Obtain each subkey P1, P2, P3, ..., P n , distribute the attributes and each sub-key to the sub-trusted management point, where P i =f(i);

[0022] (107)Destroy polynomials.

[0023] 3. Furthermore, in step (2), the specific process of attribute classification and attribute certificate generation is as follows:

[0024] (201) The user submits his / her own information to the attribute authority AA;

[0025] (202) The attribute authority AA divides the attributes into common attributes A and graded attributes CA, and sends the graded attributes to the attribute grade point ACP for user grade judgment;

[0026] (203) First, ACP normalizes the hierarchical attributes. Suppose there are m hierarchical attributes A i , corresponding to the user's hierarchical attribute security level L i and hierarchical attribute weight ω i , the user classification method is as follows:

[0027]

[0028] User security level L u ∈{Public, Restricted, Secret, Confidential, Top Secret} represents the security level obtained by the user after attribute classification. The Public level is the lowest security level and can be accessed by all visitors; the Top Secret level is the highest access level in the entire system and is very sensitive to users;

[0029] (204) The attribute classification point ACP returns the result to the attribute authority AA, and the AA generates an attribute certificate for relevant tags such as user security level and user attributes.

[0030] The beneficial effects brought about by adopting the above technical solution are:

[0031] (1) Divide users into security levels, extract classification attributes as the standard for user security level assessment, and process access requests in a more detailed manner to meet security requirements.

[0032] (2) Introduce attribute certificates, which serve as user identity credentials during the access process to improve the overall security of the system.

[0033] (3) Generate subkeys for resources. Based on Shamir secret sharing, the read and write operation keys are split to define a read and write separation authorization method. Authorization decisions are made on user requests through attributes, achieving multi-level security for user access, protecting the confidentiality of resources, and reducing the possibility of resource leakage and permission abuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is an access control model based on multi-level security and secret sharing.

[0035] Figure 2 It is an attribute certificate based on multi-level security. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0037] like Figure 1 As shown, the access control authorization method based on multi-level security and secret sharing proposed by the present invention has the following steps:

[0038] Step 1: The system divides resources into security levels. Then, initialization data such as secrets, thresholds, and prime numbers are set according to the security level, and subkeys are generated. The system administrator distributes each subkey and its matching attributes to each trusted management point for storage.

[0039] Step 2: The user sends an attribute certificate request to the attribute authority (AA). The AA first queries the attribute certificate registration center (ACR) to see if there is a user application record. If so, it extracts the ACRL from the certificate repository (ACRL) and returns it to the AA. Otherwise, the attributes are sent to the attribute classification point (ACP). The ACP classifies the user attributes into classified attributes, performs a security classification on the user based on the classified attributes, and returns the result to the AA. The AA then sends the attribute certificate back to the user.

[0040] Step 3: The user sends an authorization request Req to the request execution point QEP;

[0041] Step 4: The QEP verifies the AA signature and other information. If it passes, it sends the attributes to the trusted management point to request the subkey. The trusted management point verifies the attributes and returns the subkey if it meets the requirements. Otherwise, it returns nothing.

[0042] Step 5: The QEP sends the request and subkey set to the policy administration point PAP. The PAP compares the request with the resource permission table. If they match, the resource is returned and authorized; otherwise, it is rejected.

[0043] In this embodiment, the above step 1 can be implemented by adopting the following preferred solution:

[0044] 101. First, divide the resource Object into security levels and read the secret as S r , the secret is stored by the policy administration point PAP;

[0045] 102. Take large prime numbers P for read and write permissions respectively r ,Here we try to choose a larger prime number to ensure non-repeatability;

[0046] 103. Determine the read threshold RT r and write threshold WT r ,The read and write threshold of each resource is determined by the resource security level, and the high security level threshold is higher than the low security level threshold;

[0047] 104. Determine the number of key holders n. For read and write operations, in order to ensure the confidentiality principle of BLP, we stipulate that any resource must ensure that the number of key holders is different, and the number of key holders of each resource must be greater than or equal to max(RT, Wt);

[0048] 105. Generate the polynomial f(x) as follows:

[0049] f(x)=S r +a1x+a2x 2 +a3x 3 +…+a t-1 x t-1 (1-1)

[0050] Among them, S r Indicates resource read secret, a1, a2, a3, ..., a t-1 Indicates that from 1-P r Randomly pick t-1 numbers from the finite field;

[0051] 106. Obtain each subkey P1, P2, P3, ..., P n , distribute the attributes and each sub-key to the sub-trusted management point, where P i =f(i);

[0052] 107. Destroy polynomials;

[0053] 108. Distribute each subkey and matching attribute to each trusted management point for storage.

[0054] In this embodiment, the following preferred solution can be used to implement the above step 2:

[0055] 201. The user submits his / her own information to the attribute authority AA;

[0056] 202. The attribute authority AA divides the attributes into common attributes A and graded attributes CA, and sends the graded attributes to the attribute grade point ACP for user grade judgment;

[0057] 203. First, ACP normalizes the hierarchical attributes. Suppose there are m hierarchical attributes A i , corresponding to the user's hierarchical attribute security level L i and hierarchical attribute weight ω i , the user classification method is as follows:

[0058]

[0059] User security level L u ∈{Public, Restricted, Secret, Confidential, Top Secret} represents the security level obtained by the user after attribute classification. The Public level is the lowest security level and can be accessed by all visitors; the Top Secret level is the highest access level in the entire system and is very sensitive to users;

[0060] 204. The attribute classification point ACP returns the result to the attribute authority AA, and AA generates an attribute certificate for the user security level, user attributes and other related tags, such as Figure 2 ,The attribute certificate contains the attribute certificate subject and digital signature. The attribute certificate subject may contain information such as version number, holder, and issuer.

Claims

1. An access control authorization method based on multi-level security and secret sharing, characterized in that: The following steps are involved: (1) During the system initialization phase, the user's resource operation permissions are restricted and managed based on the Shamir secret sharing scheme. First, the resources are divided into security levels, and a secret S is preset for each resource. The Shamir secret sharing scheme is used to divide S into n unrelated parts of information. Each part of information is a subkey. The system administrator distributes each subkey and its matching attributes to each trusted management point for storage. (2) The user sends an attribute certificate request to the attribute authority AA. The AA first queries the attribute certificate registration center ACR to see if there is a user application record. If so, it extracts the ACRL from the certificate library ACRL and returns it to the attribute authority AA. Otherwise, the attributes are sent to the attribute classification point ACP. The ACP divides the user attributes and the classification attributes, performs security classification on the user based on the classification attributes, and returns the result to the AA. The AA then sends the attribute certificate back to the user. (3) The user sends an authorization request Req to the request execution point QEP; (4) QEP verifies the AA signature and other information. If it passes, it sends the attribute to the trusted management point to request the subkey. The trusted management point verifies the attribute and returns the subkey if it meets the requirements. Otherwise, it returns nothing. (5) QEP sends the request and subkey set to the policy management point PAP. PAP compares the request with the resource permission table. If it matches, it returns the resource and authorizes it. Otherwise, it rejects it.

2. The access control authorization method based on multi-level security and secret sharing according to claim 1, characterized in that: The specific process of generating the subkey in step (1) is as follows: (101) First, divide the resource Object into security levels and read the secret as S r , the secret is stored by the policy administration point PAP; (102) Take large prime numbers P for read and write permissions respectively r ,Here we choose a larger prime number to ensure non-repeatability; (103) Determine the read threshold RT r and write threshold WT r ,The read and write threshold of each resource is determined by the resource security level, and the high security level threshold is higher than the low security level threshold; (104) Determine the number of key holders n, that is, the number of subkeys into which the secret S is divided. For read and write operations, in order to ensure the confidentiality principle of BLP, we stipulate that any resource must ensure that the number of key holders is different, and the number of key holders of each resource must be greater than or equal to max(RT,WT); (105) Generate the polynomial f(x) as follows: f(x)=S r +a1x+a2x 2 +a3x 3 +…+a t-1 x t-1 (1-1) Among them, S r Indicates resource read secret, a1, a2, a3, ..., a t-1 Indicates that from 1-P r Randomly pick t-1 numbers from the finite field; (106) Obtain each subkey P1, P2, P3, ..., P n , distribute the attributes and each sub-key to the sub-trusted management point, where P i =f(i); (107)Destroy polynomials.

3. The access control authorization method based on multi-level security and secret sharing according to claim 1, characterized in that: The specific process of attribute classification and attribute certificate generation in step (2) is as follows: (201) The user submits his / her own information to the attribute authority AA; (202) The attribute authority AA divides the attributes into common attributes A and graded attributes CA, and sends the graded attributes to the attribute grade point ACP for user grade judgment; (203) First, ACP normalizes the hierarchical attributes. Suppose there are m hierarchical attributes A i , corresponding to the user's hierarchical attribute security level L i and hierarchical attribute weight ω i , the user classification method is as follows: User security level L u ∈{Public, Restricted, Secret, Confidential, Top Secret} represents the security level obtained by the user after attribute classification. The Public level is the lowest security level and can be accessed by all visitors; the Top Secret level is the highest access level in the entire system and is very sensitive to users; (204) The attribute classification point ACP returns the result to the attribute authority AA, and the AA generates an attribute certificate for relevant tags such as user security level and user attributes.

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