CISSP Guide Maps Security Models to Confidentiality and Integrity Scenarios

Summary

A CISSP study guide offers a scenario-based way to distinguish security models by whether they protect confidentiality or integrity, explaining Bell-LaPadula, Biba, Clark-Wilson, Brewer-Nash, Graham-Denning, and Take-Grant.

Key points

• The guide recommends identifying what needs protection—confidentiality or integrity—and how information may flow.
• Bell-LaPadula addresses confidentiality, using rules such as no read up and no write down to limit information leakage.
• Biba addresses integrity, using no read down and no write up to prevent lower-integrity data from affecting higher-integrity data.
• Clark-Wilson protects transactional data through well-formed procedures rather than direct user access.
• Brewer-Nash restricts access to conflicting datasets within an organization.
• The guide briefly describes Graham-Denning operations for managing subject and object rights, and Take-Grant operations for transferring rights.