Information security models are frameworks that guide organizations in protecting their sensitive data and information systems. These models are essential for maintaining the core goals of security, which are often encapsulated in the CIA Triad: Confidentiality, Integrity, and Availability. Let's delve into some classic security models and their principles.

Classic Security Models

Bell-LaPadula Model

The Bell-LaPadula Model focuses on maintaining confidentiality. It categorizes both users (subjects) and files (objects) into different layers of secrecy. The model is built on three primary rules:

• Simple Confidentiality Rule (No Read-Up): Subjects can read files at their own or lower secrecy levels, but not higher.

• Star Confidentiality Rule (No Write-Down): Subjects can write to files at their own or higher secrecy levels, but not lower.

• Strong Star Confidentiality Rule (No Read Write Up Down): Subjects can only read and write files at their own secrecy level.

Biba Model