Classification and model introduction of security models

Classification of security models

• Basic model: HRU
• Confidentiality models: BLP, Chinese Wall
• Integrity model: Biba, Clark-Wilson

BLP model

The full name of (Bell-LaPadula) model is a computer security model that complies with military security policies.
Security rules of BLP model:

1. Simple security rule: Subjects with low security levels cannot read objects with high security levels.
2. Star attribute security rules: Subjects with high security levels cannot write to objects with low security levels.
3. Strong Star Property Security Rule: No reading or writing to another level is allowed.
4. Discretionary security rules: Use an access control matrix to define discretionary access controls.

Chinese Wall Model

The basis of its security policy is that the information that customers access will not conflict with the information currently at their disposal.
Security rules for Chinese Wall model access object control:

1. Once a subject has accessed an object, the subject can only access objects located in the same company data set or objects in different interest groups.
2. Within a conflict of interest group, a subject may only have access to a maximum of one corporate data set.
3. Belonging to a completely different conflict of interest group can be accessed.
4. The premise that the subject can write to the object is that the subject has not accessed any data sets belonging to other companies.
5. Information that belongs to the same corporate data collection as information that the subject has accessed may be accessed.

Biba model

is mainly used to prevent unauthorized modification of system information to ensure the information integrity of the system. This model prevents data from flowing from a low integrity level to a high integrity level.
Safety rules of Biba model:

1. Star integrity rule: A subject with a low integrity level cannot write data to an object with a high integrity level.
2. Simple integrity rule: A subject with a high integrity level cannot read data from an object with a low integrity level.
3. Invocation attribute rule: A subject with a low integrity level cannot call a program or service from an object with a high integrity level.