# Security Roles and Responsibilities
One-sentence definition: Defined accountabilities for protecting information across owners, custodians, users, and oversight bodies.
## Key Facts
- Data/Business Owner: classifies data, defines acceptable risk, approves access.
- System Owner: budgets and maintains the system meeting owner requirements.
- Custodian/Administrator: implements and operates controls, backups.
- Users: follow AUP, protect credentials, report incidents.
- Security Manager/Officer: designs program, policies, risk processes.
- Privacy Officer/DPO: oversees personal data compliance and rights handling.
- Auditor: independent assurance of control design/effectiveness.
- **Label:** **Accountability** rests with owners; responsibility is shared.
- **Verify:** check official (ISC)² CBK and current exam outline.
## Exam Relevance
- Map actions to the correct role in scenario questions.
**Mnemonic:** “Owner decides; Custodian does; User uses.”
## Mini Scenario
Q: Who approves classification labels and access rules for a dataset?
A: The data/business owner.
## Revision Checklist
- Match each role to one responsibility.
- Identify who accepts risk.
- Distinguish owner vs system owner vs custodian.
## Related
[[Security Governance]] · [[Data Classification (Governance Overview)]] · [[Acceptable Use Policy (AUP)]] · [[Security Policy Hierarchy]] · [[Compliance and Regulatory Concepts]] · [[Domain 1 - Index]]