Access control policy verification method, system and related equipment

Abstract

The present invention discloses a verification method, system and related equipment for access control policies, and relates to the field of information security technology. The verification method for access control policies includes: a policy manager in a trust evaluation subsystem calculates a trust policy based on a received identity authentication result and device collection information to generate an evaluation result; the policy manager generates a current sub-credential based on the evaluation result; the policy manager generates a credential based on the current sub-credential and historical sub-credentials; the policy manager sends the evaluation result and the credential to a policy engine in the trust evaluation subsystem; the policy engine assigns access rights to the device based on the evaluation result and generates an authorization decision result; the policy engine sends the authorization decision result and the credential to a policy execution point, wherein the policy execution point stores historical sub-credentials so that the policy execution point can verify the credential. Embodiments of the present invention can improve the security of access control.

Description

Technical Field

[0001] The present invention relates to the field of information security technology, and in particular to a verification method and system for access control strategy and related equipment. Background Art

[0002] Currently, the zero-trust architecture is developing rapidly, in which the concept of "any person / thing / object inside or outside should not be automatically trusted, and anyone / thing / object attempting to access the enterprise system should be verified before authorization" is gradually implemented in the information transmission of internal subsystems.

[0003] The access control execution method is usually completed by the trust assessment subsystem based on the device's identity authentication results and the information collected by the device. Then the policy engine assigns permissions to different trust levels. After the permission allocation is completed, the authorization decision result is transmitted to the policy execution point, and the access control engine therein implements the access control policy. Summary of the invention

[0004] After analyzing the related technologies, the inventors found that in the related technologies, the policy execution point did not verify the source of the policies sent by the trust system subsystem. Therefore, the trust granted by the policy execution point was too high, and the concept of zero trust was not implemented. Therefore, the security of the related technologies was low.

[0005] A technical problem to be solved by the embodiments of the present invention is: how to improve the security of access control.

[0006] According to the first aspect of some embodiments of the present invention, a method for verifying an access control policy is provided, comprising: a policy manager in a trust assessment subsystem calculates a trust policy based on a received identity authentication result and device collection information to generate an assessment result; the policy manager generates a current sub-credential based on the assessment result; the policy manager generates a credential based on the current sub-credential and historical sub-credentials; the policy manager sends the assessment result and the credential to a policy engine in the trust assessment subsystem; the policy engine assigns access rights to the device based on the assessment result to generate an authorization decision result; the policy engine sends the authorization decision result and the credential to a policy execution point, wherein the policy execution point stores historical sub-credentials so that the policy execution point can verify the credential.

[0007] In some embodiments, the policy manager generating the current sub-credential according to the evaluation result includes: the policy manager using the evaluation result and the current timestamp to generate a character string as the current sub-credential.

[0008] In some embodiments, the policy manager sends the evaluation results and credentials to the policy engine in the trust assessment subsystem, including: slicing the credentials according to preset slicing rules, and inserting each slice into the evaluation results according to preset insertion rules; sending the evaluation results with the inserted slices to the policy engine in the trust assessment subsystem.

[0009] In some embodiments, the policy engine assigns access rights to the device based on the evaluation results and generates an authorization decision result, including: the policy engine extracts each slice from the evaluation result with the slice inserted according to the insertion rule to obtain the original evaluation result and the credential; the policy engine assigns access rights to the device based on the original evaluation result and generates an authorization decision result.

[0010] In some embodiments, the verification method also includes: the policy execution point verifies the credential based on the historical sub-credentials in the credential and the stored historical sub-credentials; in response to the verification being successful, the policy execution point stores the current sub-credentials in the credential and executes the policy based on the authorization decision result.

[0011] In some embodiments, the sub-credential includes a timestamp when the sub-credential is generated, and an evaluation result corresponding to the sub-credential, and the policy execution point verifies the credential based on the historical sub-credentials in the credential and the stored historical sub-credentials, including: for each sub-credential in the credential, the policy execution point compares the evaluation information of the sub-credential in the credential with the same timestamp and the stored historical sub-credential for consistency; when all comparison results are consistent, the policy execution point verifies the credential as passed.

[0012] In some embodiments, the policy engine sends the authorization decision results, evaluation results, and credentials to the policy enforcement point through an encrypted channel.

[0013] According to a second aspect of some embodiments of the present invention, a trust assessment subsystem is provided, including: a policy manager, configured to perform trust policy calculations based on received identity authentication results and device collection information to generate an assessment result; generate a current sub-credential based on the assessment result; and generate a credential based on the current sub-credential and historical sub-credentials; a policy engine, configured to receive the assessment result and credential sent by the policy manager; assign access rights to the device based on the assessment result to generate an authorization decision result; and send the authorization decision result and the credential to a policy execution point, wherein the policy execution point stores historical sub-credentials so that the policy execution point can verify the credential.

[0014] In some embodiments, the policy manager is further configured to generate a string using the evaluation result and the current timestamp as the current sub-credential.

[0015] In some embodiments, the policy manager is further configured to slice the credentials according to preset slicing rules, and insert each slice into the evaluation result according to preset insertion rules; and send the evaluation result with the slices inserted to the policy engine in the trust assessment subsystem.

[0016] In some embodiments, the policy engine is further configured to extract individual slices from the assessment results with the slices inserted according to the insertion rules, obtain the original assessment results and credentials; assign access rights to the device according to the original assessment results, and generate an authorization decision result.

[0017] According to a third aspect of some embodiments of the present invention, there is provided a verification system for an access control policy, comprising: any one of the aforementioned trust assessment subsystems; and a policy execution point, configured to verify a credential based on historical sub-credentials in the credential, and stored historical sub-credentials; in response to successful verification, storing the current sub-credential in the credential, and executing the policy based on the authorization decision result.

[0018] In some embodiments, the sub-credential includes a timestamp when the sub-credential is generated, and an evaluation result corresponding to the sub-credential, and the policy execution point is further configured to compare, for each sub-credential in the credential, the evaluation information of the sub-credential in the credential with the same timestamp and the evaluation information of the stored historical sub-credential for consistency; when all comparison results are consistent, the verification result of the credential is passed.

[0019] In some embodiments, the trust assessment subsystem is further configured to send the authorization decision result, the assessment result, and the credential to the policy enforcement point through an encrypted channel.

[0020] According to a fourth aspect of some embodiments of the present invention, there is provided an access control policy verification device, comprising: a memory; and a processor coupled to the memory, wherein the processor is configured to execute any of the aforementioned access control policy verification methods based on instructions stored in the memory.

[0021] According to a fifth aspect of some embodiments of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements any of the aforementioned methods for verifying access control policies.

[0022] Some embodiments of the above invention have the following advantages or beneficial effects. By allowing the trust assessment subsystem to generate credentials and transmitting the authorization decision result together with the credentials to the policy execution point, the policy execution point can verify the issued policy. Therefore, in this process, there is no mutual trust between the trust assessment subsystem and the policy execution point, which conforms to the idea of ​​zero trust. In addition, the credential generation reflects time continuity, improves credibility, and is not easy to be forged. Therefore, the above embodiments can improve the security of access control.

[0023] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 A flowchart of a method for verifying an access control policy in the related art is exemplarily shown.

[0026] Figure 2 A schematic flow chart of a method for verifying an access control policy according to some embodiments of the present invention is shown.

[0027] Figure 3 A schematic flow chart of a credential verification method according to some embodiments of the present invention is shown.

[0028] Figure 4 A schematic diagram of the structure of a trust assessment subsystem according to some embodiments of the present invention is shown.

[0029] Figure 5 A schematic diagram of the structure of a verification system for access control policies according to some embodiments of the present invention is shown.

[0030] Figure 6 A schematic diagram of the structure of an access control policy verification device according to some embodiments of the present invention is shown.

[0031] Figure 7 A schematic diagram of the structure of an access control policy verification device according to some other embodiments of the present invention is shown. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The relative arrangement of components and steps, the numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0034] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0035] Technologies, methods, and apparatus known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, such technologies, methods, and apparatus should be considered part of the authorization specification.

[0036] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0037] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0038] Figure 1 The flowchart of the verification method of the access control policy in the related art is shown as an example. Figure 1 As shown, the verification method of this embodiment includes steps S102 to S112.

[0039] In step S102, the trust assessment subsystem receives the identity authentication result and the device collection information.

[0040] In step S104, the policy manager in the trust evaluation subsystem calculates the trust policy according to the device identity authentication result and the device collection information.

[0041] In step S106, the policy manager transmits the result of the trust policy calculation to the policy engine in the trust assessment subsystem.

[0042] In step S108, the policy engine allocates permissions to different trust levels according to the authorization policy to form an authorization decision result.

[0043] In step S110, the trust assessment subsystem sends the authorization decision result to the policy enforcement point via an encrypted channel.

[0044] In step S112, the access control engine in the policy enforcement point implements the policy decision result.

[0045] In the above process, the policy execution point did not verify the source of the policy sent by the trust system subsystem, and did not implement the concept of zero trust. In addition, in addition to channel encryption, there are no other confidentiality methods in the process. If the authorization policy is counterfeited, the policy execution point cannot defend itself.

[0046] In order to improve the security of access control, the trust evaluation subsystem in the embodiment of the present invention generates not only evaluation results, but also sub-credentials of multiple evaluation results within a period of time to form credentials, and passes the credentials to the policy execution point. Thus, the policy execution point can verify according to the credentials. Figure 2 An embodiment of a method for verifying an access control policy of the present invention is described.

[0047] Figure 2 FIG. 1 is a flow chart showing a method for verifying access control policies according to some embodiments of the present invention. Figure 2 As shown, the access control policy verification method of this embodiment includes steps S202 to S216.

[0048] In step S202, the trust assessment subsystem receives the identity authentication result and the device collection information.

[0049] In some embodiments, the terminal device sends the device collection information and the identity authentication information to the identity authentication subsystem, and the identity authentication subsystem authenticates the terminal device. If the authentication is successful, the identity authentication subsystem sends the identity authentication result and the device collection information to the trust assessment subsystem.

[0050] In step S204, the policy manager in the trust evaluation subsystem performs trust policy calculation according to the received identity authentication result and device collection information to generate an evaluation result.

[0051] The device collection information includes one or more items of information. In some embodiments, the policy manager calculates a quantifiable result based on the weighted results of each item of information as the evaluation result.

[0052] In step S206 , the policy manager generates a current sub-credential according to the evaluation result.

[0053] In some embodiments, the policy manager generates a string using the evaluation result and the current timestamp as the current sub-credential.

[0054] In step S208, the policy manager generates a credential based on the current sub-credential and the historical sub-credential.

[0055] For example, the generated credentials are {C1,C2,C3,…,C n-1 ,C n}, C n Indicates the current sub-credential, C1, C2, C3, ..., C n-1 All are historical sub-vouchers.

[0056] In some embodiments, the historical sub-credential used to generate the credential is a sub-credential within a preset time period, or a sub-credential extracted from all historical sub-credentials according to a preset extraction rule. Accordingly, the same historical sub-credential selection rule is also stored at the policy execution point for verification.

[0057] In step S210, the policy manager sends the evaluation result and the credential to the policy engine in the trust evaluation subsystem.

[0058] In some embodiments, the credentials are sliced ​​according to preset slicing rules, and each slice is inserted into the evaluation result according to preset insertion rules; the evaluation result with the inserted slices is sent to the policy engine in the trust evaluation subsystem.

[0059] Therefore, it is equivalent to encrypting the evaluation results and credentials, thereby improving the security of the transmission of the evaluation results and credentials.

[0060] In step S212, the policy engine allocates permissions based on the evaluation results and generates an authorization decision result.

[0061] In some embodiments, the policy engine extracts each slice from the assessment result with the slice inserted according to the insertion rule, obtains the original assessment result and the credential; the policy engine assigns access rights to the device according to the original assessment result, and generates an authorization decision result.

[0062] In some embodiments, the permission refers to the access rights of the terminal device to the background system. Multiple permission levels can be preset, such as full permission, read-write permission, read-only permission, etc., or high, medium, low permission levels, etc.

[0063] In some embodiments, the policy engine determines the permission level based on the correspondence between the preset allocation permissions and the quantified results of the evaluation information.

[0064] In step S214, the policy engine sends the authorization decision result and the credential to the policy enforcement point, where the policy enforcement point stores the historical sub-credentials.

[0065] The policy execution point is, for example, a gateway of a backend system.

[0066] In some embodiments, the policy engine sends the authorization decision results, evaluation results, and credentials to the policy enforcement point through an encrypted channel.

[0067] In step S216, the policy enforcement point verifies the credentials.

[0068] In some embodiments, the verification is performed by an access control module in a policy enforcement point.

[0069] If the verification passes, the process can be considered safe and the policy in the authorization decision result is valid; if the verification fails, the policy will not be executed, and risk tracing can be performed based on error logs (such as missing credentials, incorrect credential data, etc.).

[0070] In the method of the above embodiment, by making the trust assessment subsystem generate credentials, and transmitting the authorization decision result together with the credentials to the policy execution point, the policy execution point can verify the issued policy. Therefore, in this process, there is no mutual trust between the trust assessment subsystem and the policy execution point, which conforms to the concept of zero trust. In addition, the credential generation reflects the time continuity, improves the credibility, and is not easy to be forged. Therefore, the above embodiment can improve the security of access control.

[0071] Reference below Figure 3 Embodiments in which a policy enforcement point verifies credentials are described.

[0072] Figure 3 FIG. 2 is a flow chart showing a method for verifying a credential according to some embodiments of the present invention. Figure 3 As shown, the credential verification method of this embodiment includes steps S302 to S306.

[0073] In step S302, the policy enforcement point verifies the credential based on the historical sub-credential in the credential and the stored historical sub-credential.

[0074] In some embodiments, the sub-credential includes a timestamp when the sub-credential is generated and an evaluation result corresponding to the sub-credential. For each sub-credential in the credential, the policy enforcement point compares the evaluation information of the sub-credential in the credential with the same timestamp and the evaluation information of the stored historical sub-credential to see if they are consistent; if all comparison results are consistent, the policy enforcement point verifies that the credential has passed.

[0075] In step S304, in response to the verification being successful, the policy enforcement point stores the current sub-credential in the credential.

[0076] In step S306, the policy enforcement point executes the policy according to the authorization decision result.

[0077] Therefore, the current sub-credential can be used as the basis for the next verification.

[0078] In some embodiments, the policy enforcement point opens the corresponding level of permissions to the terminal device that intends to initiate access according to the permission level in the authorization decision result. If the access request of the terminal device is higher than the permission level, the access request is rejected; if the access request of the terminal device is not higher than the permission level, the access request is approved.

[0079] In some embodiments, the embodiment further includes step S308.

[0080] In step S308, in response to the verification failing, the policy enforcement point does not execute the policy in the authorization decision result and performs risk tracing.

[0081] Through the method of the above embodiment, the policy execution point can verify the credentials based on historical data, thereby realizing the source verification of the authorization decision result and improving the security of access control.

[0082] In some embodiments, the trust assessment subsystem can also insert credentials only in part of the transmission process, for example, after carrying credentials in the transmission process of the preset first number of transmissions or the first transmission duration, credentials are not carried in the transmission process of the preset second number of transmissions or the second transmission duration. The corresponding transmission policy is stored at the policy execution point. Therefore, if a certain transmission should not transmit credentials, but the policy execution point receives data with credentials, it can also prove that the source of the data is untrustworthy. Thus, the security of the system is further improved.

[0083] Reference below Figure 4 An embodiment of the trust assessment subsystem of the present invention is described.

[0084] Figure 4 FIG. 2 shows a schematic diagram of the structure of a trust evaluation subsystem according to some embodiments of the present invention. Figure 4 As shown, the trust assessment subsystem 400 of this embodiment includes: a policy manager 4100, configured to perform trust policy calculations based on the received identity authentication results and device collection information to generate an assessment result; generate a current sub-credential based on the assessment result; and generate a credential based on the current sub-credential and historical sub-credentials; a policy engine 4200, configured to receive the assessment results and credentials sent by the policy manager; assign access rights to the device based on the assessment results to generate an authorization decision result; and send the authorization decision result and the credential to a policy execution point, wherein the policy execution point stores historical sub-credentials so that the policy execution point can verify the credential.

[0085] In some embodiments, the policy manager 4100 is further configured to generate a string using the evaluation result and the current timestamp as the current sub-credential.

[0086] In some embodiments, the policy manager 4100 is further configured to slice the credentials according to preset slicing rules, and insert each slice into the evaluation result according to preset insertion rules; and send the evaluation result with the slices inserted to the policy engine in the trust assessment subsystem.

[0087] In some embodiments, the policy engine 4200 is further configured to extract individual slices from the assessment results with the slices inserted according to the insertion rules, obtain the original assessment results and credentials; assign access rights to the device according to the original assessment results, and generate an authorization decision result.

[0088] Reference below Figure 5 An embodiment of a verification system for access control policies of the present invention is described.

[0089] Figure 5 FIG. 1 is a schematic diagram showing a structure of a verification system for access control policies according to some embodiments of the present invention. Figure 5 As shown, the access control policy verification system 50 of this embodiment includes a trust evaluation subsystem 510 and a policy enforcement point 520 .

[0090] For a specific implementation of the trust evaluation subsystem 510, refer to Figure 4 The trust assessment subsystem 400 in the embodiment will not be described in detail here.

[0091] The policy enforcement point 520 is configured to verify the credential based on the historical sub-credentials in the credential and the stored historical sub-credentials; in response to successful verification, the policy enforcement point stores the current sub-credential in the credential and executes the policy based on the authorization decision result.

[0092] In some embodiments, the sub-credential includes a timestamp when the sub-credential was generated and an evaluation result corresponding to the sub-credential, and the policy execution point 520 is further configured to compare, for each sub-credential in the credential, the evaluation information of the sub-credential in the credential with the same timestamp and the evaluation information of the stored historical sub-credential for consistency; when all comparison results are consistent, the verification result of the credential is passed.

[0093] In some embodiments, the policy enforcement point 520 includes an access control module 5200 .

[0094] In some embodiments, the policy enforcement point 520 is a gateway of a backend system.

[0095] In some embodiments, the trust assessment subsystem 510 is further configured to send the authorization decision result, the assessment result, and the credential to the policy enforcement point 520 through an encrypted channel.

[0096] Figure 6The schematic diagram of the structure of the access control policy verification device according to some embodiments of the present invention is shown. The access control policy verification device in this embodiment is a trust assessment subsystem or a policy execution point. Figure 6 As shown, the access control policy verification device 60 of this embodiment includes: a memory 610 and a processor 620 coupled to the memory 610, and the processor 620 is configured to execute the access control policy verification method in any of the aforementioned embodiments based on instructions stored in the memory 610.

[0097] The memory 610 may include, for example, a system memory, a fixed non-volatile storage medium, etc. The system memory may store, for example, an operating system, an application program, a boot loader, and other programs.

[0098] Figure 7 FIG. 1 is a schematic diagram showing a structure of an access control policy verification device according to some other embodiments of the present invention. The access control policy verification device in this embodiment is a trust assessment subsystem or a policy execution point. Figure 7 As shown, the access control policy verification device 70 of this embodiment includes: a memory 710 and a processor 720, and may also include an input / output interface 730, a network interface 740, a storage interface 750, etc. These interfaces 730, 740, 750 and the memory 710 and the processor 720 may be connected, for example, via a bus 760. Among them, the input / output interface 730 provides a connection interface for input / output devices such as a display, a mouse, a keyboard, and a touch screen. The network interface 740 provides a connection interface for various networked devices. The storage interface 750 provides a connection interface for external storage devices such as SD cards and USB flash drives.

[0099] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements any of the aforementioned methods for verifying access control policies.

[0100] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable non-transient storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0101] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0102] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0103] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0104] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for verifying an access control policy, comprising: The policy manager in the trust evaluation subsystem calculates the trust policy based on the received identity authentication result and the device collection information to generate an evaluation result; The policy manager generates a current sub-credential according to the evaluation result; The policy manager generates a credential based on the current sub-credential and the historical sub-credential; The policy manager sends the evaluation result and the credential to the policy engine in the trust evaluation subsystem; The policy engine assigns access rights to the device according to the evaluation result and generates an authorization decision result; The policy engine sends the authorization decision result and the credential to a policy enforcement point, wherein the policy enforcement point stores historical sub-credentials so that the policy enforcement point can verify the credential.

2. The verification method according to claim 1, wherein: The policy manager generates the current sub-credential according to the evaluation result, including: The policy manager generates a character string using the evaluation result and the current timestamp as the current sub-credential.

3. The verification method according to claim 1, wherein: The policy manager sending the evaluation result and the credential to the policy engine in the trust evaluation subsystem includes: Slicing the voucher according to a preset slicing rule, and inserting each slice into the evaluation result according to a preset insertion rule; The evaluation result with the slice inserted is sent to the policy engine in the trust evaluation subsystem.

4. The verification method according to claim 3, wherein: The policy engine assigns access rights to the device according to the evaluation result, and generates an authorization decision result including: The policy engine extracts each slice from the evaluation result with the slice inserted according to the insertion rule to obtain the original evaluation result and the credential; The policy engine allocates access rights to the device according to the original evaluation result and generates an authorization decision result.

5. The verification method according to claim 1, further comprising: The policy enforcement point verifies the credential based on the historical sub-credential in the credential and the stored historical sub-credential; In response to the verification being passed, the policy enforcement point stores the current sub-credential in the credential and executes policy according to the authorization decision result.

6. The verification method according to claim 5, wherein: The sub-credential includes a timestamp when the sub-credential is generated and an evaluation result corresponding to the sub-credential, and the policy execution point verifies the credential according to the historical sub-credential in the credential and the stored historical sub-credential, including: For each sub-credential in the credential, the policy enforcement point compares the evaluation information of the sub-credential in the credential with the same timestamp and the evaluation information of the stored historical sub-credential to see whether they are consistent; When all comparison results are consistent, the policy enforcement point verifies that the credential has passed.

7. The verification method according to claim 1, wherein: The policy engine sends the authorization decision result, the evaluation result and the credential to the policy execution point through an encrypted channel.

8. A trust assessment subsystem, comprising: A policy manager is configured to calculate a trust policy based on the received identity authentication result and the device collection information to generate an evaluation result; generating a current sub-credential according to the evaluation result; and, generating a credential based on the current sub-credential and the historical sub-credential; A policy engine is configured to receive the evaluation result and the credential sent by the policy manager; assign access rights to the device according to the evaluation result and generate an authorization decision result; and send the authorization decision result and the credential to a policy enforcement point, wherein the policy enforcement point stores historical sub-credentials so that the policy enforcement point can verify the credential.

9. The trust assessment subsystem according to claim 8, wherein: The policy manager is further configured to generate a character string using the evaluation result and a current timestamp as a current sub-credential.

10. The trust assessment subsystem according to claim 8, wherein: The policy manager is further configured to slice the credentials according to a preset slicing rule, and insert each slice into the evaluation result according to a preset insertion rule; And, sending the evaluation results with the slices inserted to the policy engine in the trust evaluation subsystem.

11. The trust assessment subsystem according to claim 10, wherein: The policy engine is further configured to extract each slice from the evaluation result with the slice inserted according to the insertion rule, obtain the original evaluation result and the credential; assign access rights to the device according to the original evaluation result, and generate an authorization decision result.

12. A verification system for an access control policy, comprising: The trust assessment subsystem according to any one of claims 8 to 11; as well as The policy execution point is configured to verify the credential based on the historical sub-credentials in the credential and the stored historical sub-credentials; in response to the verification being passed, store the current sub-credential in the credential, and execute the policy based on the authorization decision result.

13. The verification system according to claim 12, wherein: The sub-credential includes a timestamp when the sub-credential is generated and an evaluation result corresponding to the sub-credential, and the policy execution point is further configured to: for each sub-credential in the credential, compare the evaluation information of the sub-credential in the credential with the same timestamp and the evaluation information of the stored historical sub-credential for consistency; when all comparison results are consistent, the verification result of the credential is passed.

14. The verification system according to claim 12, wherein: The trust evaluation subsystem is further configured to send the authorization decision result, the evaluation result and the credential to a policy enforcement point through an encrypted channel.

15. A verification device for an access control policy, comprising: Memory; as well as A processor coupled to the memory, the processor being configured to execute the access control policy verification method according to any one of claims 1 to 7 based on instructions stored in the memory.

16. A computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the method for verifying the access control policy according to any one of claims 1 to 7 is implemented.

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