CN104794410B - A kind of database security protection method based on reliable computing technology - Google Patents

Abstract

The invention discloses a database security protection method based on trusted computing technology, which uses the basis for the implementation of database security mechanisms such as authentication, access control, and auditing—identity information, authorization information, audit configuration information, and audit logs of database management systems. Security-related data is based on the credibility of the system environment and hardware security, preventing the adversary from tampering with the above basis and then affecting the database security mechanism to achieve various attack purposes. Based on the method, a security chip-based secure database system for storing sensitive data can be established to ensure that the security-related data of the database security mechanism will not be tampered with, thereby improving the security of the security mechanism of the database management system.

Description

A database security protection method based on trusted computing technology

technical field

The invention proposes a database security protection method based on trusted computing technology, which belongs to the field of database security.

Background technique

With the development of informatization, more and more data is stored in the database. Whether it is external threats such as viruses, Trojan horses, hacker attacks, or malicious behavior of internal personnel, it can have a serious impact on the database system. In order to deal with these threats, the security database uses various security mechanisms such as authentication, access control, auditing and so on. However, security databases do not provide sufficient protection against the basis for the implementation of these mechanisms. Once these database security-related data are tampered with, it will have an extremely serious impact on the database system. Therefore, in order to deal with the data security threat brought by the hysteresis of the security protection measures of the database system security mechanism itself, it is necessary to carry out security protection for the database security-related data stored in the database.

However, the existing database security technology has the following two significant defects that cannot ensure the security of these security-related data: First, the protection of security-related data is not bound to the security of the environment. Traditional database security-related data integrity protection measures are usually based on the premise that the environment is relatively safe, for example, there are no viruses, Trojan horses, etc. in the operating system, and this assumption is difficult to establish. In the case that the system environment has been destroyed, the security database cannot guarantee the integrity of the security-related data even if the integrity protection is carried out. This is due to the lack of detection of the security of the system environment when measuring the integrity of safety-related data, resulting in the integrity measurement value itself generated by safety-related data in a non-safety environment is not credible, and the integrity measurement based on this value Sex tests are even more unreliable. Moreover, in the absence of detection of the security of the system environment, the verification result of the integrity measurement value can also be tampered with, which is also untrustworthy.

Second, the protection of security-related data is not based on hardware. The integrity protection of traditional database security-related data is usually based on the security of the system's Trusted Computing Base (TCB) implemented in software. The TCB implemented by this software cannot completely prevent attackers from tampering with security-related data. For example, once the insiders who can access the database system are malicious, they can tamper with security-related data without being easily detected, causing serious damage. loss. This is a problem that cannot be solved by a secure database solution that lacks hardware support.

In short, the current security database still lacks a database security protection method that can safely store database security-related data and bind the implementation of its security mechanism with the security of the system environment and underlying hardware.

Contents of the invention

In view of the above problems, the present invention provides a database security protection method based on trusted computing technology, which can ensure that the basis for the implementation of the database security mechanism is credible, that is, identity information, access control authorization information, audit configuration information and audit logs Integrity protection is carried out, and its integrity is bound to the system environment and underlying hardware, so that tampering of these database security-related data by remote attackers or insiders can be effectively discovered.

The basic principle of this technology is: use the signature key generated by the security chip TCM/TPM to sign and protect the integrity measurement value of the table storing identity information, authorization information, audit configuration information and audit logs and other security-related data in the database. The secure system environment in which this signing key is used. Since the signing key is protected by the hardware of the security chip, the attacker cannot obtain the key directly, so the signature cannot be forged. At the same time, since the use environment of the signature key is the security state of the database, an attacker cannot use the signature key to sign tampered data by tampering with the database management system TCB.

In order to achieve the above object, the present invention adopts the following technical solutions:

A database security protection method based on trusted computing technology. On the basis of a database management system TCB, the security protection of the database is realized through a security chip and a trusted measurement module. The method specifically includes:

1) The system adopting this method implements secure startup based on a security chip, and builds a chain of trust, which includes a trusted measurement module and a database management system TCB; at the same time, the security chip generates a signature key, and the signature key The use environment of the key is specified as this trust chain environment;

2) When writing security-related data into the database through the security mechanism, firstly, the security status of the current database management system TCB is credibly measured through the trusted measurement module; if the current database management system TCB is in a secure Sign the integrity measurement value of the security-related data with the key, and store the security-related data and the signature value together in the database;

3) When reading the security-related data from the database through the security mechanism, firstly, the security status of the current database management system TCB is credibly measured by the trusted measurement module; if the current database management system TCB is in a security status, then the Verify the integrity of the read signature value and safety-related data (compare the currently obtained integrity value with the integrity value obtained in step 2, and if they are the same, it is safe).

Further, the security mechanism includes: an authentication mechanism, an access control mechanism, and an audit mechanism, and the security-related data includes: identity information, authorization information, audit configuration information, and audit logs; the authentication mechanism is responsible for The information is identified; the access control mechanism is responsible for access control based on the authorization information stored in the database; the audit mechanism is responsible for auditing based on the audit configuration information stored in the database.

Further, the writing process of the identity information includes the following steps:

1-a) Obtain the identity information of the user through the authentication mechanism, and request the signature key of the security chip;

1-b) Use the trusted measurement module to perform trusted measurement on the security status of the current database management system TCB;

1-c) If the database management system TCB is in a secure state, the authentication mechanism uses the signature key to sign the integrity value of the identity information, and then stores the information and the signature value together in the database.

Further, the process of reading the identity information includes the following steps:

2-a) The authentication mechanism reads the identity information and its signature value from the database;

2-b) The authentication mechanism verifies the integrity of the signature value and identity information. If the detection is passed, the subsequent authentication operation can be performed; otherwise, the authentication failure is reported.

Further, the writing process of the authorization information includes the following steps:

3-a) Obtain the authorization information of the security administrator through the access control mechanism, and request the signature key of the security chip;

3-b) Use the trusted measurement module to perform trusted measurement on the security status of the current database management system TCB;

3-c) If the database management system TCB is in a secure state, the access control mechanism uses the signature key to sign the integrity value of the authorization information, and then stores the authorization information and the signature value together in the database.

Further, the reading process of the authorization information includes the following steps:

4-a) The access control mechanism reads the authorization information and its signature value from the database;

4-b) The access control mechanism verifies the integrity of the signature value and authorization information. If it passes the detection, perform access control according to the authorization information; otherwise, report verification failure.

Further, the writing process of the audit configuration information includes the following steps:

5-a) Obtain the audit configuration information of the audit administrator through the audit mechanism, and request the signature key of the security chip;

5-b) Use the trusted measurement module to perform trusted measurement of the security status of the current database management system TCB;

5-c) If the database management system TCB is in a secure state, the audit mechanism uses the signature key to sign the integrity value of the audit configuration information, and then stores the information and the signature value in the database.

Further, the reading process of the audit configuration information includes the following steps:

6-a) The audit mechanism reads configuration information and its signature value from the database;

6-b) The audit mechanism verifies the integrity of the signature value and configuration information. If it passes the test, it will be audited according to this configuration information, otherwise it will report verification failure.

Further, the writing process of the audit log includes the following steps:

7-a) The audit mechanism requests the signature key of the security chip before auditing records;

7-b) Use the trusted measurement module to perform trusted measurement of the security status of the current database management system TCB;

7-c) If the database management system TCB is in a secure state, the audit mechanism uses the signature key to sign the integrity value of the audit record, and then stores the audit record and the signature value together in the database.

Further, the above steps also include: modifying the format of the original audit log, adding two columns of attributes to store the count value and the integrity value respectively, and each time an audit record is generated, the audit mechanism will query the information provided by the security chip. The current count value of the monotonic counter, and use the signature key of the security chip to sign and store the integrity value of the record together with the counter value.

Further, the reading process of the audit log includes the following steps:

8-a) The audit mechanism reads the audit log and its signature value from the database;

8-b) The audit mechanism verifies the signature value and the integrity of the audit record. If it passes the detection, the subsequent audit query analysis operation can be performed, otherwise, the report verification failure is reported.

The beneficial effects of the present invention are:

The present invention establishes the implementation basis of database security mechanisms such as authentication mechanism, access control mechanism, and audit mechanism—security-related data such as identity information, access control authorization information, audit configuration information, and audit logs on the basis of system environment credibility and hardware security. Above all, to prevent the adversary from tampering with the above basis and then affecting the database security mechanism to achieve various attack purposes. When the above security-related data needs to be used, the present invention will verify the integrity of these data to ensure that these data have not been illegally tampered with. Before the integrity verification, the present invention will also use the credible measurement technology to check the system environment to ensure that the verification result is credible. In addition, the signing key of security-related data is encrypted and protected by a hardware security chip, thus realizing hardware-based security. Therefore, it is ensured that the security-related data of the database security mechanism will not be tampered with, thereby improving the security of the security mechanism of the database management system.

Description of drawings

Fig. 1 is a schematic diagram of a database security protection method architecture based on trusted computing technology.

detailed description

The specific implementation of the key technical modules described in the summary of the invention will be explained below as examples, but the scope of the invention will not be limited by this explanation.

The structure of the database security protection method based on trusted computing technology in the present invention is shown in FIG. 1 , which mainly includes a security chip TCM/TPM, a trusted measurement module, an authentication mechanism, an access control mechanism and an audit mechanism in the database management system TCB. Among them, the security chip is responsible for providing the root of trust and signature key; the trusted measurement module is responsible for the trusted measurement of processes or files in the system environment based on the trust chain formed after the system starts; the authentication mechanism is responsible for The identity information is used for identity confirmation; the access control mechanism is responsible for access control based on the authorization information stored in the database; the audit mechanism is responsible for auditing based on the audit configuration information stored in the database.

Firstly, introduce the two basic modules, the security chip module and the trusted measurement module. The present invention needs to use some of the functions provided by them, but the implementation of the modules themselves is not within the scope of the present invention. The functions involved in the present invention will be explained below.

1. Security chip

The functions or mechanisms that need to be provided by the security chip in the present invention are mainly measurement root of trust and key protection functions. The metric root of trust is the foundation upon which the chain of trust of the system protected by the security chip is built. There are many ways to construct the trust chain from the root of trust to the trusted measurement module, such as static measurement. The key protection function is the security protection provided by the security chip for the key generated by it. Usually, the security chip has a storage root key SRK (Storage Root Key), which is established when the chip is initialized and kept in the chip to prevent attackers from obtaining it. SRK can be used as a parent key to create an asymmetric key pair, and declare the use environment of the private key in this key pair (realized by specifying the environmental measurement value stored in the security chip), and encrypt the private key and store it in the security chip external. When using this private key for signature or decryption, the private key must be loaded into the security chip for use, that is, it will be decrypted by SRK inside the security chip. Two purposes are thus achieved: first, the security of the key is based on the hardware chip; second, the environment in which the key is used must meet expectations. Finally, the security chip mentioned in the present invention may be a domestically produced TCM chip, or a TPM chip or other software and hardware that provide the above-mentioned functions. The storage root key of the security chip mentioned in the content of the present invention refers to the public-private key pair used for encryption and decryption generated and protected by the security chip, and does not necessarily refer to the SRK. Similarly, the signature key mentioned above also refers to the public-private key pair used for signature generated and protected by the security chip.

2. Credible measurement module

The trusted measurement module is located in the kernel layer of the operating system and is measured during the process of building the trust chain at system startup, so it is located in the TCB of the entire system. The present invention needs the function provided by it to measure the integrity of any process started in the system environment and extend the measurement result to the security chip.

The specific embodiment of the present invention will be set forth below:

The essence of the database security protection method based on trusted computing technology is to use trusted computing technology to enhance the traditional database security function. The specific implementation will involve the transformation of the security function of the original database management system:

An integrity verification process should be added to the original authentication mechanism, that is, after the authentication mechanism receives an authentication request, it must verify the integrity of the identity information stored in the system table before implementing authentication based on the identity information. Identity information is usually only authenticated once, and multiple visits may be performed, which will not have too much impact on the efficiency of the entire database system. Therefore, the integrity verification process can be directly added to the code of the authentication function.

The original access control mechanism needs to add an integrity verification process, that is, after the access control mechanism receives an access request, it must verify the integrity of the authorization data stored in the system table before implementing access control based on the authorization data. Since the industrial control system has high requirements for efficiency, if the integrity verification process is added to the access control process for each data access, the efficiency will be greatly reduced. Therefore, the integrity verification process can be separately implemented as an extension module of the database, and a switch function can be set to enable or disable the integrity verification process in the access control process according to different application scenarios.

The transformation of the audit mechanism is divided into two aspects: On the one hand, the audit mechanism must first verify the integrity of the information related to the audit configuration before implementing the audit record operation on the database. However, unlike the modification of the access control mechanism, the audit configuration information is usually only read once when the database is started, and will not affect the efficiency of the entire database system. Therefore, the integrity verification process can be directly added to the audit function. in the code. On the other hand, audit logs, as the basis for subsequent analysis, must ensure their credibility. Therefore, it is necessary to protect the integrity of the log when the audit mechanism generates the audit log. First of all, based on the fact that audit logs usually contain many records, the integrity protection of the record level should be used instead of the entire log when implementing integrity protection; secondly, the integrity protection of the record level can only ensure that an attacker cannot tamper with a single audit record , but there is no way to verify whether an attacker deleted or added audit records. Therefore, it is necessary to additionally use the monotonic counter provided by the security chip for the audit log. Specifically, the format of the original audit log needs to be modified, and two columns of attributes are added to store the count value and integrity value respectively. Every time an audit record is generated, the audit mechanism should query the value of the current monotonic counter, and use the signature key of the security chip to sign and store the integrity value of the record together with the counter value. Since the monotonic counter is protected by the security chip and cannot be tampered with, its value can only increase but not decrease, so the deletion or addition of audit records by an attacker can be verified by checking the count value.

Claims (9)

1. a kind of database security protection method based on reliable computing technology, on the basis of data base management system TCB, lead to The safeguard protection of safety chip and the realization of credible metric module to database is crossed, this method specifically includes：

1) safety chip startup with high safety is based on using the system of this method, and builds trust chain, the trust chain includes Credible metric module and data base management system TCB；Meanwhile the safety chip produces a signature key, the signature key Use environment be appointed as this trust chain environment；

2) when writing safety-relevant data into database by security mechanism, first by credible metric module to current number Credible measurement is carried out according to base management system TCB safe condition；If current data base management system TCB is in a safe condition, The integrity measurement value of the safety-relevant data is signed using signature key, and by the safety-relevant data and signature Value is stored in database together, and the security mechanism includes Audit Mechanism, and the safety-relevant data includes audit configuration information And audit log；The Audit Mechanism is used to be audited according to the audit configuration information stored in database, the audit day The write-in flow of will comprises the following steps：

2-1) form of original audit log is modified, two Column Properties of increase are respectively used to stored count value and integrality Value；

2-2) Audit Mechanism asks the signature key of safety chip before record of the audit is carried out；

2-3) credible measurement can be carried out to current data base management system TCB safe condition using credible metric module；

When 2-4) producing record of the audit every time, the current of the monotone counter provided by safety chip is all inquired about by Audit Mechanism Count value, if data base management system TCB is in a safe condition, Audit Mechanism is then using the signature key of safety chip to the note The integrity value and Counter Value of record carry out signing together and in data storage storehouses；

3) when reading the safety-relevant data from database by security mechanism, first by credible metric module to working as Preceding data base management system TCB safe condition carries out credible measurement；If current data base management system TCB is in safe shape State, then the signature value and the integrality of safety-relevant data that are read are verified.

2. the database security protection method based on reliable computing technology as claimed in claim 1, it is characterised in that the peace Full mechanism includes：Authentication mechanism and access control mechanisms, the safety-relevant data include：Identity information and authorization message；Institute Authentication mechanism is stated to be used to carry out identity validation according to the identity information stored in database；The access control mechanisms are used for basis The authorization message stored in database conducts interviews control.

3. the database security protection method based on reliable computing technology as claimed in claim 2, it is characterised in that the body The write-in flow of part information comprises the following steps：

The identity information of user 1-a) is obtained by authentication mechanism, and asks the signature key of safety chip；

Credible measurement 1-b) is carried out to current data base management system TCB safe condition using credible metric module；

If 1-c) data base management system TCB is in a safe condition, authentication mechanism is then using signature key to the complete of identity information Whole property value is signed, and is then stored in the information and signature value in database together.

4. the database security protection method based on reliable computing technology as claimed in claim 3, it is characterised in that the body The reading flow of part information comprises the following steps：

2-a) authentication mechanism reads out identity information and its signature value from database；

2-b) authentication mechanism checking signature value and the integrality of identity information, if by detection, can carry out follow-up certification Operation, otherwise reporting authentication failure.

5. the database security protection method based on reliable computing technology as claimed in claim 2, it is characterised in that described to award The write-in flow of power information comprises the following steps：

The authorization message of safety officer 3-a) is obtained by access control mechanisms, and asks the signature key of safety chip；

Credible measurement 3-b) is carried out to current data base management system TCB safe condition using credible metric module；

If 3-c) data base management system TCB is in a safe condition, access control mechanisms are then using signature key to authorization message Integrity value signed, then authorization message and signature value are stored in database together.

6. the database security protection method based on reliable computing technology as claimed in claim 5, it is characterised in that described to award The reading flow of power information comprises the following steps：

4-a) access control mechanisms read out authorization message and its signature value from database；

4-b) the integrality of access control mechanisms checking signature value and authorization message, if by detection, according to this authorization message Conduct interviews control, and otherwise reporting authentication fails.

7. the database security protection method based on reliable computing technology as claimed in claim 1, it is characterised in that described to examine The write-in flow of meter configuration information comprises the following steps：

5-a) be audited the audit configuration information of keeper by Audit Mechanism, and asks the signature key of safety chip；

5-b) credible measurement can be carried out to current data base management system TCB safe condition using credible metric module；

If 5-c) data base management system TCB is in a safe condition, Audit Mechanism is then using signature key to configuration information of auditing Integrity value signed, then the information and signature value are stored in database together.

8. the database security protection method based on reliable computing technology as claimed in claim 7, it is characterised in that described to examine The reading flow of meter configuration information comprises the following steps：

6-a) Audit Mechanism reads out configuration information and its signature value from database；

6-b) Audit Mechanism checking signature value and the integrality of configuration information, if by detection, are carried out according to this configuration information Audit, otherwise reporting authentication failure.

9. the database security protection method based on reliable computing technology as claimed in claim 1, it is characterised in that described to examine The reading flow of meter daily record comprises the following steps：

8-a) Audit Mechanism reads out audit log and its signature value from database；

8-b) Audit Mechanism checking signature value and the integrality of record of the audit, if by detection, can carry out follow-up audit Query analysis operates, and otherwise reporting authentication fails.