📘 Topic: Hierarchical Security Model

Domain: D5 – Identity and Access Management
Tags: #cissp

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🧾 Definition

A hierarchical security model organizes subjects and objects into ordered levels and uses the structure to enforce access rules. It is closely associated with lattice-based and mandatory access control approaches.

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🔑 Key Points

• Access is determined by a clear ordering of security levels.
• A common example is the Bell-LaPadula model, which enforces confidentiality by restricting reads and writes.
• This is a mandatory model, not a simple role hierarchy.
• It is particularly relevant for environments that require strict labels and classification.

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⚠️ CISSP Insight

• CISSP candidates should understand the purpose of the model and how it differs from DAC or RBAC.
• It is important for highly sensitive environments where data classification is enforced by the system.

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⚔️ Key Difference / Trap

• Hierarchical model vs role hierarchy
  • Hierarchical security model = labels and mandatory access rules
  • Role hierarchy = organizational grouping of permissions
• Not the same as general “manager/subordinate” hierarchy

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🏗️ Example

A Top Secret document can only be read by users with Top Secret clearance, while users at lower levels cannot access it.

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📚 References

• Bell-LaPadula Model
• NIST SP 800-53, AC-3
• ISC2 CISSP CBK, Domain 5

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🔁 Quick Recall

• Hierarchical model = label-based access
• Mandatory + classification = key idea