WO2011150650A1

WO2011150650A1 - Method and device for key authorization information management

Info

Publication number: WO2011150650A1
Application number: PCT/CN2010/080294
Authority: WO
Inventors: 郎风华; 尹瀚; 宋成
Original assignee: 华为技术有限公司
Priority date: 2010-06-01
Filing date: 2010-12-27
Publication date: 2011-12-08
Also published as: CN102270285B; CN102270285A

Abstract

A method and a device for key authorization information management are disclosed, the method involves: judging whether the key authorization value requested to use by a user is same with the key authorization value in a key storage module (101); judging whether the key timestamp in the key storage module is same with the timestamp in the key timestamp certificate (102), the timestamp in the timestamp certificate expresses the time when the user appointed the key authorization value for the last time; when the key authorization value requested to use by the user is same with the key authorization value in the key storage module and the key timestamp in the key storage module is same with the timestamp in the key timestamp certificate, it is determined that the user is entitled to use the key (103). The application detects the authorization value and the key timestamp simultaneously so that an attacker can not use the key due to the difference of the key timestamps even if the attacker copies the original key storage module and acquires the authorization value before modification, thus the safety of key using is enhanced.

Description

Key Authorization Information Management Method and Apparatus The present application claims to be submitted to the Chinese Patent Office on June 1, 2010, and the application number is 201010192499. 2, the priority of the Chinese patent application entitled "Key Authorization Information Management Method and Apparatus" The entire contents of which are incorporated herein by reference. The present invention relates to the field of encryption technologies, and in particular, to a key authorization information management method and apparatus. BACKGROUND A Trusted Platform (TPM) module is a chip that is built in a computer to provide a trusted root for a computer. The TPM integrates a CPU core, a RAM, a ROM, an F lash encryption algorithm, and a co-processing. Modules such as random number generators.

The TPM is actually a small system-on-chip that contains cryptographic components and storage components. Data storage in the TPM is more reliable than in other storage units such as PCs and servers, and it is impossible for any device to write directly to the TPM.

The TPM generates a number of keys, one for each authorized value. However, since the internal storage space of the TPM is limited, it is impossible to store all the keys in the TPM, so the S torage Root Key (SRK) and its authorized value are stored in the storage area inside the TPM. The other keys and their authorized values are stored in encrypted form in an external key storage module. When it is necessary to modify the authorization value of a key, the key storage module is first loaded into the TPM for decryption, and then the key authorization value update protocol is invoked, and according to the old authorization value input by the user, it is confirmed whether the key is authorized to operate the key. If yes, replace the old authorization value with the new authorization value entered by the user and save it to the key storage module. When determining whether the user has the right to use the key, the TPM first loads the key storage module into the TPM for decryption, extracts the authorization value from it, and compares it with the authorized value input by the user. If the two are the same, the user has the right. The key is used, otherwise the user does not have access to the key.

In the process of implementing the present invention, the inventors have found that the prior art has at least the following disadvantages: It can be seen from the above process that determining whether the user has the right to use the key key depends on whether the authorization value of the key input by the user is correct. If the attacker previously knows the authorization value and copies the key storage module, even if the user subsequently modifies The authorization value in the key storage module, the attacker can also use the key by using the TRM to load the key storage module before the modification, and use the key according to the previous authorization value, thereby causing the key to be illegally used. Summary of the invention

The embodiment of the invention provides a key authorization information management method and device, which can prevent the key from being illegally used.

The method for managing key authorization information includes:

Determining whether the authorization value of the key requested by the user is the same as the authorization value of the key in the key storage module;

Determining whether the timestamp of the key in the key storage module is the same as the timestamp in the timestamp certificate of the key, and the timestamp in the timestamp certificate indicates the time when the user last specified the key authorization value;

When the authorization value of the key requested by the user is the same as the authorization value of the key in the key storage module, and the time stamp of the key in the key storage module is related to the key When the timestamps in the timestamp certificate are the same, it is determined that the user has the right to use the key.

The key authorization information management apparatus includes:

An authorization value judging module, configured to determine whether an authorization value of a key requested by the user is the same as an authorization value of the key in the key storage module;

a timestamp determining module, configured to determine whether a timestamp of the key in the key storage module is the same as a timestamp in the timestamp certificate of the key; the timestamp certificate is stored in a timestamp certificate module, The timestamp in the timestamp certificate indicates the time when the user last specified the key authorization value; a key usage determining module, configured to: when an authorization value of a key requested by the user is the same as an authorization value of the key in the key storage module, and the key in the key storage module When the timestamp is the same as the timestamp in the timestamp certificate of the key, it is determined that the user has the right to use the key.

When the user requests to use the key, the embodiment of the present invention needs to determine whether the authorization value input by the user is the same as the authorization value saved in the key storage module, and determine the timestamp and the time in the timestamp certificate stored in the key storage module. Whether the stamps are the same; if both judgments are yes, it is determined that the user has the right to use the key, because the timestamp in the timestamp certificate indicates the time when the user last authorized the authorized value of the key, if the user has modified The authorization time, the timestamp in the timestamp certificate is the time when the user last modified the authorization value, so even if the attacker copies the original key storage module (that is, the key storage module before the authorization value is modified) and obtains the modification. The previous authorization value, because the timestamp in the original key storage module is different from the timestamp in the timestamp certificate, the key cannot be used to prevent the key from being illegally used. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings may be obtained based on these drawings without any creative work.

FIG. 1 is a flowchart of a method for managing key authorization information according to an embodiment of the present invention;

2 is a flowchart of a method for generating a time stamp certificate of a key according to an embodiment of the present invention; FIG. 3 is a flowchart of a method for generating a time stamp certificate of a key according to another embodiment of the present invention; A flowchart of a method for determining a key usage right provided by an embodiment;

5A is a structural diagram of a key authorization information management apparatus according to an embodiment of the present invention; and FIG. 5B is a structural diagram of another key authorization information management apparatus according to an embodiment of the present invention. detailed description Referring to FIG. 1, an embodiment of the present invention provides a method for managing key authorization information, where the method includes:

101. Determine whether an authorization value of a key requested by the user is the same as an authorization value of the key in the key storage module.

102. Determine whether the timestamp of the key in the key storage module is the same as the timestamp in the timestamp certificate of the key, and the timestamp in the timestamp certificate indicates that the user last specified the key authorization value. time.

Specifically, if the user does not modify the authorization value of the key after inputting the authorization value, the timestamp in the timestamp certificate is the time when the user first inputs the authorization value; if the user modifies the authorization value of the key, The timestamp in the timestamp certificate is the time when the user last modified the authorization value.

The timestamp certificate includes: the timestamp, a key identifier, and a digital signature; the digital signature is a timestamp and an identifier using an attestation identity key (Attrastat Ident I ty Key, ΑΙΚ) The signature of the key identifier.

The key identifier is a unique identifier information of the key, such as a key handle or a universal unique identifier (Uniform ID) of the key, and the timestamp in the embodiments of the present invention may be The value of the monotonic counter built into the TPM. The key storage module in each embodiment of the present invention is a data block external to the TPM.

In order to ensure the validity of the timestamp certificate used in the step, the step further includes: verifying, according to the digital signature in the timestamp certificate of the key, whether the timestamp certificate of the key is legal, and if so, performing the judgment. The step of whether the timestamp of the key in the key storage module is the same as the timestamp in the timestamp certificate of the key.

103. The authorization value of the key requested by the user is the same as the authorization value of the key in the key storage module, and the timestamp of the key in the key storage module is the same as the secret When the timestamp in the key's timestamp certificate is the same, it is determined that the user has the right to use the key.

In the embodiment of the present invention, the timestamp needs to be obtained in the following two cases: The first case: when receiving the key generation request instruction input by the user, generating a key, and obtaining an authorization value input by the user, and acquiring the current value of the counter as the first time stamp, which needs to be stored in the key storage module and The information to be encrypted is encrypted and saved in the key storage module; and the first time stamp and the key identifier are signed, and a time stamp certificate is generated. The information that needs to be stored in the key storage module and needs to be encrypted includes the first timestamp and an authorization value, and the information that needs to be encrypted further includes a private key and some other information in the key.

The second case: when receiving the authorization value change instruction input by the user, acquiring the current value of the counter as the second timestamp, and replacing the existing time of the key in the key storage module with the second timestamp Stamping, replacing the existing authorization value of the key in the key storage module with a new authorization value input by the user; and signing the second timestamp and the key identifier to generate a new timestamp certificate, The new timestamp certificate replaces the original timestamp certificate of the key.

When the user requests to use the key, the embodiment of the present invention needs to determine whether the authorization value input by the user is the same as the authorization value of the key stored in the key storage module, and determine the time of the key stored in the key storage module. Whether the timestamp in the timestamp certificate of the key is the same, if both judgments are yes, it is determined that the user has the right to use the key, because the timestamp in the timestamp certificate indicates that the user last modified The time at which the key is authorized, so even if the attacker copies the original key storage module (that is, the key storage module before the authorization value is modified) and obtains the authorization value before the modification, due to the original key storage module The timestamp of the key is different from the timestamp in the timestamp certificate of the key, so the key cannot be used to prevent the key from being used illegally.

In order to explain the technical solutions of the embodiments of the present invention more clearly, the following describes the key authorization information management method provided by the present invention in three stages based on the TPM platform:

The first stage: a key generation phase, in which a timestamp is added to the key storage module while the key is generated, and a timestamp certificate is generated according to the added timestamp. Referring to FIG. 2, the stage includes:

201. Receive a key generation request instruction input by a user.

When the user wants to generate a key, a key generation request instruction input by the user is received. 202. Generate a key according to the key generation request instruction, and acquire an authorization value of the key input by the user.

Specifically, the key generation command in the TPM may be generated according to the key generation request instruction.

TPM.Crea teKey, generates a key. The key generated in this step includes a public key and a private key.

203. Obtain a value of the built-in monotonic counter as a first timestamp.

Specifically, you can call the TPM_ReadCounter command (which is the counter read command) to get the value of the built-in monotonic counter.

204. Encrypt the information that needs to be stored in the key storage module and needs to be encrypted, obtain the encrypted information, and save the encrypted information and the public information into the key storage module.

The information that needs to be stored in the key storage module and needs to be encrypted includes a first timestamp, an authorization value, a private key, and other information. Public information includes: public keys, key identifiers, and other information.

The key storage module includes a plurality of key data blocks, and each key data block is used to store encrypted information and public information of one key. This step is to save the encrypted information and the public information to a key data block in the key storage module.

205. Sign the first timestamp and the key identifier to generate a timestamp certificate, where the timestamp certificate includes: a first timestamp, a key identifier, and a digital signature.

Specifically, the first timestamp and the key identifier may be signed by calling the A I K inside the TPM.

206. Save the timestamp certificate to the timestamp certificate storage module.

When generating a key, the embodiment obtains a timestamp, saves the timestamp to a key storage module outside the TPM, and generates a timestamp certificate, so that the subsequent user needs to use the key by using the key storage module. The timestamp of the key is compared to the timestamp in the timestamp certificate of the key to determine if the user is authorized to use the key.

Phase 2: Change the Authorization Value phase, in which a new timestamp certificate is generated while changing the authorization value, and the original timestamp certificate is replaced with a new timestamp certificate. See Figure 3, which includes:

301. Received an authorization value change instruction input by a user. When the user wants to change the authorization value, he receives an authorization value change instruction input by the user.

302. Load the key data block corresponding to the key in the key storage module into the TPM, and decrypt the encrypted information part by using some public information (such as a public key) in the key data block to obtain an authorized value and time. Poke and other information.

For the specific decryption method, refer to the prior art, and details are not described herein again.

303. Receive an old authorization value input by the user.

304. Determine whether the old authorization value input by the user is the same as the decrypted authorization value. If yes, go to step 305. If no, end the process.

305. Determine to allow the user to modify the authorization value, and receive a new authorization value input by the user.

Specifically, the change authorization value command TPM_ChangeAuth in the TPM can be used to determine whether the old authorization value input by the user is the same as the decrypted authorization value, and receives the new authorization value input by the user.

306. Obtain a value of the built-in monotonic counter as a second timestamp.

Specifically, you can call the TPM_ReadCounter command to get the value of the built-in monotonic counter.

307. Encrypt the information that needs to be stored in the key storage module and needs to be encrypted, and replace the encrypted information of the key originally stored in the key storage module with the new encrypted information obtained by the encryption.

The information that needs to be stored in the key storage module and needs to be encrypted includes a second timestamp, an authorization value newly input by the user, a private key, and other information.

The specific implementation process of the step may be as follows: Fill the new encrypted information and the public information into the key data block of the key in the key storage module, and the original encrypted information and the public key in the key data block of the key Information coverage.

308. Sign the second timestamp and the key identifier to generate a new timestamp certificate, where the timestamp certificate includes: a second timestamp, a key identifier, and a digital signature.

Specifically, the second timestamp and the key identifier can be signed by the AIK.

309. Replace the timestamp certificate of the key originally stored in the timestamp certificate storage module with the new timestamp certificate. When the user changes the authorization value, the embodiment obtains a timestamp, replaces the timestamp of the key stored in the key storage module with a new timestamp, and generates a new timestamp certificate by using the new timestamp. The new timestamp certificate replaces the original timestamp certificate of the key, so that when the subsequent user wants to use the key, the timestamp of the key in the key storage module is timed with the timestamp certificate of the key. The stamp is compared to determine if the user is authorized to use the key.

The third stage: determining the user's key usage authority phase, in which the authorization value entered by the user is determined to be the same as the authorization value of the key stored in the key storage module, and the key storage module is determined to be saved. The timestamp of the key is the same as the timestamp in the timestamp certificate of the key to determine whether the user has the right to use the key. Referring to FIG. 4, the stage specifically includes:

401. Receive a key usage request instruction input by a user.

When the user wants to use the key, the key usage request instruction input by the user is received.

402. Load the key data block of the key in the key storage module into the TPM, and decrypt the encrypted information part by using some public information (such as a public key) in the key data block to obtain an authorization value, a timestamp, and Information such as key identification.

403. Receive an authorization value of a key input by the user.

404. Determine whether the authorization value of the key input by the user is the same as the authorized value obtained by the decryption. If yes, go to step 405. If no, go to step 409.

Specifically, the TPM-Cha nge Au t h can be used to determine whether the authorization value input by the user is the same as the decrypted authorization value by calling the change authorization value command in the TPM.

405. Obtain a timestamp certificate of the key from the timestamp certificate storage module according to the key identifier in the key data block.

406. Determine whether the timestamp certificate is legal. If yes, go to step 407. If no, go to step 409. Specifically, it is determined whether the timestamp certificate is legal according to the digital signature in the timestamp certificate. due to

AIK is a non-migrating signature key. Any data signed by AIK indicates that it has been processed by TPM, which means it is legal.

407. Determine whether the timestamp of the key in the key storage module is the same as the timestamp in the timestamp certificate of the key. If yes, go to step 408. If no, go to step 409.

Specifically, it is determined whether the timestamp obtained by the decryption step 401 is the same as the timestamp in the timestamp certificate of the key.

408. Determine that the user has the right to use the key, operate the key, and end the process.

409. Determine that the user does not have the right to use the key, and prompts an error message.

It should be noted that, in the step 406, the location of the timestamp certificate is not fixed. For example, it may be determined whether the timestamp certificate is legal after determining whether the timestamp is the same, and may be adjusted according to the actual situation (for example, according to the actual situation). The processing complexity and the time consuming are both performed first, and the steps that are easy to implement or consume less time are executed first, and are not limited herein.

In the embodiment of the present invention, when the user requests to use the key, it is required to determine whether the authorization value input by the user is the same as the authorization value of the key stored in the key storage module, determine whether the timestamp certificate is legal, and determine the key storage module. The timestamp of the saved key is the same as the timestamp in the timestamp certificate of the key; if all three judgments are yes, it is determined that the user has the right to use the key, thus, because the timestamp certificate The timestamp indicates the time when the user last modified the authorization value of the key, so even if the attacker copies the original key storage module (that is, the key storage module before the authorization value is modified) and obtains the authorization value before the modification, The timestamp of the key in the key storage module is different from the timestamp in the timestamp certificate, so the key cannot be used to prevent the key from being illegally used.

Referring to FIG. 5A, an embodiment of the present invention provides a key authorization information management apparatus, including: an authorization value determining module 501, configured to determine an authorization value of a key requested by a user and the key in a key storage module. Whether the authorization values are the same; The timestamp judging module 502 is configured to determine whether the timestamp of the key in the key storage module is the same as the timestamp in the timestamp certificate of the key, and the timestamp in the timestamp certificate indicates the user last time The time when the key authorization value is specified;

a key usage determining module 503, configured to: when an authorization value of a key requested by the user is the same as an authorization value of the key in the key storage module, and the key in the key storage module When the timestamp is the same as the timestamp in the timestamp certificate of the key, it is determined that the user has the right to use the key.

Specifically, referring to FIG. 5B, the embodiment of the present invention further includes:

The timestamp certificate verification module 504, the encryption and decryption module 505, the reception processing module 506, and the time stamp management module 507.

In the embodiments of the present invention, each module may be implemented based on a TPM platform or a system having a similar hardware architecture. For example, in the embodiment of the present invention, the timestamp certificate is stored in the timestamp certificate storage module, and the timestamp certificate storage module and the key storage module are stored in an external memory independent of the TPM platform (for example, in a file). The form is stored in the system hard drive).

The key storage module includes one or more key data blocks, and each key data block includes encrypted information and public information. The encrypted information includes an authorized value, a private key, a timestamp, and other information, and the public information includes: a key identifier, a public key, and other information.

The timestamp certificate storage module includes one or more timestamp certificates, wherein each timestamp certificate includes a key identifier, a digital signature, and a timestamp. The digital signature here may be a signature of the timestamp and key identification using the proof of identity key AIK.

In the embodiment of the present invention, the timestamp certificate verification module 504 is configured to verify whether the timestamp certificate of the key is legal according to the digital signature in the timestamp certificate of the key used by the user. Specifically, the timestamp certificate verification module 504 can verify whether the timestamp certificate of the key is legal according to the digital signature in the timestamp certificate of the key when the determination result of the authorization value judgment module 501 is YES; if legal, Then, the timestamp judgment module 502 determines the timestamp, and finally determines whether the user has the right to use the key through the key use determining module 503; if not, the key use determining module 503 directly determines that the user does not have the right to use the key. . It should be noted that the location of the timestamp certificate verification module 504 is not fixed. In a specific implementation, the timestamp determination module 502 may first determine the timestamp, and then verify the timestamp certificate by the timestamp certificate verification module 504. Legitimacy can be adjusted according to the actual situation (for example, according to the complexity and time consumption of the two, the steps that are easy to implement or consume less time are executed first), and are not limited herein.

In the embodiment of the present invention, the receiving processing module 506 is configured to receive a key generation request instruction input by the user, and receive an authorization value of the key input by the user.

The timestamp management module 507 is configured to: after receiving the key generation request instruction, use the current value of the counter as the first timestamp; for example, when the embodiment of the present invention is based on the TPM platform, the value of the monotonic counter inside the TPM can be used. Come as the first timestamp;

The encryption and decryption module 505 is configured to encrypt the information that needs to be stored in the key storage module and needs to be encrypted, and save the obtained encryption information into the key storage module, where the information needs to be stored in the key storage module. And the information that needs to be encrypted includes the first timestamp and the authorization value, and further includes a private key and other information;

The timestamp management module 507 is further configured to: sign the first timestamp and the key identifier, generate a timestamp certificate, and store the timestamp certificate into the timestamp certificate storage module.

In the embodiment of the present invention, the receiving processing module 506 is further configured to receive an authorization value change instruction input by the user, and receive a new authorization value of the key input by the user, in order to obtain the timestamp and modify the authorization value.

The timestamp management module 507 is further configured to: after receiving the authorization value change instruction, obtain the current value of the counter as the second timestamp;

The encryption and decryption module 505 is further configured to encrypt information that needs to be stored in the key storage module and needs to be encrypted, and replace the existing key in the key storage module with the new encrypted information obtained by the encryption. Encrypting information, where the information that needs to be stored in the key storage module and needs to be encrypted includes the second timestamp and the new authorization value, and further includes a private key and other information; The timestamp management module 507 is further configured to: sign the second timestamp and the key identifier, generate a new timestamp certificate, and replace the new timestamp certificate with an existing one in the timestamp certificate storage module. The timestamp certificate of the key.

It should be noted that the encryption/decryption module 505 is used for decrypting the encrypted information in the key storage module in addition to the encryption. For example, after receiving the relevant user instruction by the receiving processing module, the data in the obtained key data block is decrypted, and information such as an authorized value and a time stamp is obtained for use by the authorization value judging module and the time stamp management module.

When the user requests to use the key, the embodiment of the present invention needs to determine whether the authorization value input by the user is the same as the authorization value of the key stored in the key storage module, and determine the time of the key stored in the key storage module. Whether the timestamp in the timestamp certificate of the key is the same; if both judgments are yes, it is determined that the user has the right to use the key, because the timestamp in the timestamp certificate indicates that the user last modified The time at which the key is authorized, so even if the attacker copies the original key storage module (that is, the key storage module before the authorization value is modified) and obtains the authorization value before the modification, since the original key storage module The timestamp of the key is different from the timestamp in the timestamp certificate of the key, so the key cannot be used to prevent the key from being used illegally.

A person skilled in the art can understand that all or part of the steps of implementing the above embodiments may be performed by a program to instruct related hardware, and the program may be stored in a computer readable storage medium, such as a read only memory. Disk or disc, etc.

The foregoing detailed description of the method and apparatus for managing the key authorization information provided by the embodiments of the present invention is only for helping to understand the method and core idea of the present invention. Meanwhile, for those skilled in the art, according to the present invention, The present invention is not limited by the scope of the present invention.

Claims

Rights request

A key authorization information management method, comprising:

2. The method of claim 1 wherein:

The timestamp certificate includes: a timestamp, a key identifier, and a digital signature; the digital signature is a signature of the timestamp and the key identifier by using the attestation identity key A I K .

3. The method according to claim 1, further comprising:

Determining whether the timestamp certificate of the key is legal according to the digital signature in the timestamp certificate of the key, and if so, determining the timestamp of the key in the key storage module and the time of the key Whether the timestamps in the certificate are the same.

The method according to any one of claims 1-3, wherein the method further comprises: when receiving a key generation request instruction input by the user, generating a key, and acquiring an authorization value input by the user, obtaining The current value of the counter is used as the first timestamp, and the information that needs to be stored in the key storage module is encrypted and saved in the key storage module; wherein the need to be stored in the key storage module and required The encrypted information includes the first timestamp and an authorization value;

And signing the first timestamp and the key identifier to generate a timestamp certificate.

The method according to any one of claims 1 to 3, further comprising: when receiving an authorization value change instruction input by a user, acquiring a current value of the counter as a second time stamp, receiving user input New authorization value, replacing the key storage module with the second timestamp The timestamp of the key in the key, and replacing the existing authorization value of the key in the key storage module with the new authorization value;

Signing the second timestamp and the key identification, generating a new timestamp certificate, and replacing the original timestamp certificate of the key with the new timestamp certificate.

A key authorization information management apparatus, comprising:

a timestamp determining module, configured to determine whether a timestamp of the key in the key storage module is the same as a timestamp in the timestamp certificate of the key; the timestamp certificate is stored in a timestamp certificate module, The timestamp in the timestamp certificate indicates the time when the user last specified the key authorization value; the key usage determining module is configured to use the authorization value of the key requested by the user and the secret in the key storage module The authorization value of the key is the same, and when the timestamp of the key in the key storage module is the same as the timestamp in the timestamp certificate of the key, it is determined that the user has the right to use the key.

7. Apparatus according to claim 6 wherein:

8. The device according to claim 6, further comprising:

a timestamp certificate verification module, configured to verify, according to the digital signature in the timestamp certificate of the key, whether the timestamp certificate of the key is legal;

The timestamp judging module is configured to: when the timestamp certificate verification module verifies that the timestamp certificate of the key is legal, determine the timestamp of the key in the key storage module and the timestamp certificate storage module Whether the timestamps in the timestamp certificate of the key are the same.

The device according to any one of claims 6-8, further comprising: a receiving processing module, configured to receive a key generation request instruction input by the user, and receive an authorization value of the key input by the user; a timestamp management module, configured to: after receiving the key generation request instruction, use a current value of the counter as the first timestamp;

And an encryption and decryption module, configured to encrypt information that needs to be stored in the key storage module and needs to be encrypted, and save the obtained encrypted information into the key storage module;

The timestamp management module is further configured to: sign the first timestamp and the key identifier, generate a timestamp certificate, and store the timestamp certificate into the timestamp certificate storage module.

10. Apparatus according to claim 9 wherein:

The receiving processing module is further configured to receive an authorization value change instruction input by the user, and receive a new authorization value of the key input by the user;

The timestamp management module is further configured to: after receiving the authorization value change instruction, acquire the current value of the counter as the second timestamp;

The encryption and decryption module is further configured to encrypt information that needs to be stored in the key storage module and needs to be encrypted, and replace the existing key in the key storage module with new encrypted information obtained by encryption. Encrypted information;

The timestamp management module is further configured to: sign the second timestamp and the key identifier, generate a new timestamp certificate, and replace the new timestamp certificate with the existing one in the timestamp certificate storage module. The timestamp certificate of the key.