hardMultiple ChoiceObjective-mapped
200-201 Practice Question: To protect sensitive data at rest, a company uses…
To protect sensitive data at rest, a company uses AES-256 encryption. This primarily ensures which security goal?
⚠ Common exam trap
Cisco often tests the distinction between encryption (confidentiality) and hashing (integrity), so the trap here is confusing AES-256's role in protecting data from unauthorized reading with the ability to detect tampering, which would require a separate integrity mechanism.
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
✓
Confidentiality
AES-256 encryption transforms plaintext data into ciphertext using a 256-bit symmetric key, rendering it unreadable without the correct decryption key. This directly ensures confidentiality by preventing unauthorized access to the stored data, even if the storage medium is compromised.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Confidentiality
Why this is correct
Encryption protects data from unauthorized disclosure.
- ✗
Availability
Why it's wrong here
Availability ensures data is accessible when needed; encryption doesn't guarantee that.
- ✗
Integrity
Why it's wrong here
Integrity is about preventing unauthorized modification, not encryption.
- ✗
Non-repudiation
Why it's wrong here
Non-repudiation prevents denial of actions, typically via digital signatures.
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 |
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-201 practice question is part of Courseiva's free Cisco 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 200-201 exam.