# Clark-Wilson Integrity Model
One-sentence definition: Commercial integrity model using **well-formed transactions**, **constrained data items (CDIs)**, and **separation of duties**.
## Key Facts
- Users perform via transformation procedures (TPs) that preserve integrity.
- IVP (Integrity Verification Procedure) validates CDIs remain consistent.
- Enforces access triplet: user–TP–CDI; auditors verify rules.
- Emphasizes SoD, auditing, and application controls (not just MAC/DAC).
- Ideal for financial systems and ERPs.
- **Verify:** check official (ISC)² CBK and current exam outline.
## Exam Relevance
- Pick model with transaction controls and auditing.
**Mnemonic:** “**W**ell-formed **T**ransactions keep **C**DIs clean.”
## Mini Scenario
Q: Same person creates and approves payments—violation?
A: Breaks SoD under Clark-Wilson; requires separate TPs/roles.
## Revision Checklist
- Define CDI, TP, IVP.
- Contrast with Biba’s lattice approach.
- Identify SoD/audit importance.
## Related
[[Biba Integrity Model]] · [[Bell-LaPadula (BLP) Model]] · [[Segmentation, DMZs, and Zero Trust Architecture]] · [[Secure Design Principles (Saltzer & Schroeder)]] · [[Threat Modeling (STRIDE, Attack Surface)]] · [[Domain 3 - Index]]