How can you ensure the confidentiality, integrity, and availability of information using security models?

1 Bell-LaPadula Model

The Bell-LaPadula model is a security model that focuses on confidentiality, which means preventing unauthorized access to information. It is based on the concept of security levels, which are labels assigned to subjects (users or processes) and objects (data or resources). The model enforces two main rules: the simple security property and the *-property. The simple security property states that a subject can only read an object if its security level is equal to or higher than the object's security level. The *-property states that a subject can only write to an object if its security level is equal to or lower than the object's security level. These rules prevent information leakage from high to low security levels.

2 Biba Model

The Biba model is a security model that focuses on integrity, which means maintaining the accuracy and consistency of information. It is based on the concept of integrity levels, which are labels assigned to subjects and objects. The model enforces two main rules: the simple integrity property and the *-property. The simple integrity property states that a subject can only read an object if its integrity level is equal to or lower than the object's integrity level. The *-property states that a subject can only write to an object if its integrity level is equal to or higher than the object's integrity level. These rules prevent information corruption from low to high integrity levels.

3 Clark-Wilson Model

The Clark-Wilson model is a security model that focuses on both confidentiality and integrity, but also on accountability, which means tracking the actions and responsibilities of subjects. It is based on the concept of well-formed transactions, which are operations that preserve the consistency and security of the system. The model enforces three main rules: the separation of duty rule, the certification rule, and the enforcement rule. The separation of duty rule states that a subject can only perform a transaction if it has the appropriate authorization and role. The certification rule states that a subject can only access an object if it is certified by a trusted entity. The enforcement rule states that a subject can only access an object through a predefined interface that ensures the validity of the transaction.

4 Brewer-Nash Model

The Brewer-Nash model is a security model that focuses on availability, which means ensuring the accessibility and usability of information. It is based on the concept of dynamic conflicts of interest, which are situations where a subject may compromise the security of the system by accessing multiple objects that are related or competitive. The model enforces one main rule: the Chinese wall policy. The Chinese wall policy states that a subject can only access an object if it does not belong to a conflict class that contains an object that the subject has already accessed. This rule prevents information disclosure or misuse that may harm the interests of the system or its stakeholders.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?