DEA-C01 Data Store Management Practice Question
A data engineer is designing a data lake on Amazon S3. The data includes personally identifiable information (PII) that must be encrypted at rest. Which combination of actions meets the encryption requirement with the least operational overhead?
⚠ Common exam trap
Many candidates confuse enforcing encryption (via bucket policies) with actually encrypting data at rest, or they overcomplicate the solution by choosing SSE-KMS or client-side encryption when SSE-S3 provides sufficient security with the least operational overhead.
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
✓
Enable default encryption on the S3 bucket using SSE-S3
Enabling default encryption on the S3 bucket with SSE-S3 automatically encrypts all objects at rest using AES-256, managed entirely by AWS. This requires no additional configuration or key management, providing the least operational overhead while meeting the encryption requirement for PII.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Apply a bucket policy that denies access to unencrypted requests
Why it's wrong here
Bucket policy does not encrypt data.
- ✓
Enable default encryption on the S3 bucket using SSE-S3
Why this is correct
SSE-S3 is simple and automatically encrypts objects.
- ✗
Use client-side encryption with AWS KMS
Why it's wrong here
Client-side encryption adds complexity.
- ✗
Use server-side encryption with AWS KMS (SSE-KMS)
Why it's wrong here
SSE-KMS provides more control but more overhead.
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 |
Go deeper
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DEA-C01 practice question is part of Courseiva's free Amazon Web Services 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 DEA-C01 exam.