DEA-C01 Data Security and Governance Practice Question
A company stores sensitive data in an Amazon S3 bucket. To comply with regulations, all data must be encrypted at rest using server-side encryption. The security team wants to ensure that any attempt to upload an unencrypted object is automatically denied. Which S3 bucket policy condition should be used?
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
✓
s3:x-amz-server-side-encryption
The s3:x-amz-server-side-encryption condition key enforces that objects must be encrypted with AES-256 (SSE-S3). s3:x-amz-server-side-encryption-aws-kms-key-id is for KMS key enforcement. s3:x-amz-acl controls access control lists, not encryption.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
s3:x-amz-server-side-encryption-aws-kms-key-id
Why it's wrong here
This enforces a specific KMS key, but the requirement is simply to encrypt, not to use a particular key.
- ✗
s3:x-amz-acl
Why it's wrong here
This controls access control lists, not encryption.
- ✓
s3:x-amz-server-side-encryption
Why this is correct
Setting this condition to require 'AES256' enforces SSE-S3 encryption.
- ✗
s3:x-amz-storage-class
Why it's wrong here
This controls storage class, not encryption.
Visual reference
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 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.