ISC Security Planning And Engineering Practice Question
Which TWO controls are recommended under NIST SP 800-53 for protecting data at rest in a high-impact system?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Role-Based Access Control (RBAC).
Encryption (AES-256) and strong access controls (RBAC) are standard for high-impact data protection.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Role-Based Access Control (RBAC).
Why this is correct
Ensures that only authorized users access the data.
- ✗
Storing data only in the local cache.
Why it's wrong here
Cache is volatile and not a strategy for protecting data at rest.
- ✗
Disabling all audit logging.
Why it's wrong here
Logging is mandatory for high-impact systems.
- ✗
Using cleartext storage for performance.
Why it's wrong here
Cleartext is never acceptable for high-impact systems.
- ✓
AES-256 encryption.
Why this is correct
Standard for high-impact data protection.
Quick reference
Symmetric Encryption Algorithm Comparison
| Algorithm | Key Size | Block Size | Status | Notes |
|---|---|---|---|---|
| AES-128 | 128-bit | 128-bit | Current standard | NIST approved; WPA3, TLS |
| AES-256 | 256-bit | 128-bit | Current standard | Preferred for sensitive / govt data |
| 3DES | 112-bit effective | 64-bit | Deprecated (2023) | Replaced by AES |
| DES | 56-bit | 64-bit | Broken | Cracked in < 24 h; never deploy |
| ChaCha20 | 256-bit | Stream cipher | Current | TLS 1.3, WireGuard |
About these practice questions
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official (ISC)² exam blueprint
This ISC practice question is part of Courseiva's free (ISC)² certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the ISC exam.