Certified Information Systems Security Professional (CISSP) Practice Exam

Which model is designed to ensure the integrity of objects within a security context?

1. Bell-LaPadula model

2. Biba model

3. Kerberos model

4. Stateful inspection model

The correct answer is: Biba model

The Biba model is designed specifically to ensure the integrity of objects within a security context. It focuses on maintaining data integrity and preventing unauthorized users from modifying data in an unauthorized manner. The fundamental principle of the Biba model is that it employs two main rules: the *simple integrity property*, which prevents users from writing to a higher integrity level (no write up), and the *star integrity property*, which prevents users from reading from a lower integrity level (no read down). This dual approach helps to ensure that data can only be altered by authorized users and that information flows in a manner that preserves its integrity. In contrast to Biba, the Bell-LaPadula model primarily focuses on confidentiality and controls access to sensitive data based on security classifications. Kerberos is an authentication protocol that facilitates secure user identity verification, while the Stateful inspection model relates to network security and analyzes the state of active connections to determine whether a packet is in line with established security policies. Each of these models serves a specific purpose and addresses different aspects of security, but for maintaining integrity specifically, the Biba model stands out as the most relevant.