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Biba Model Explained — Security Models (Part 3)

Security Architecture & EngineeringCISSP

Biba is the integrity twin of Bell-LaPadula — same two-rule skeleton, completely reversed direction and goal. In Part 3 of our Security Models series, we break down Biba's formal properties, how it contrasts with Bell-LaPadula, and where its integrity-only design leaves gaps.

What you will learn

• What the Biba model is and how it mirrors Bell-LaPadula
• The Simple Integrity Property (no read down) and the Star Integrity Property (no write up)
• The Invocation Property — a third rule closing an indirect route around the first two
• Why Biba has no discretionary layer or trusted-subject exception, unlike Bell-LaPadula
• Biba's tradeoff: integrity only, no confidentiality, no covert-channel protection

Part of the series: Security Models Explained — Overview (Part 1)

1. Security Models Explained — Overview (Part 1)
2. Bell-LaPadula Model Explained — Security Models (Part 2)
3. Biba Model Explained — Security Models (Part 3)
4. Clark-Wilson Model Explained — Security Models (Part 4)
5. Brewer-Nash Model Explained — Security Models (Part 5)
6. Graham-Denning Model Explained — Security Models (Part 6)
7. Harrison-Ruzzo-Ullman (HRU) Model Explained — Security Models (Part 7)
8. Take-Grant Model Explained — Security Models (Part 8)
9. Noninterference Model Explained — Security Models (Part 9)

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• Secure Access Service Edge (SASE) Explained