DEA-C01 Data Store Management Practice Question
A company is using Amazon S3 to store sensitive data. They need to ensure that all objects are encrypted at rest. Which combination of actions should be taken? (Choose TWO.)
⚠ Common exam trap
Many candidates confuse data protection features like Versioning or MFA Delete with encryption controls, or assume that network policies (Access Points) somehow enforce encryption, when in reality only explicit bucket policies and default encryption settings directly ensure objects are encrypted at rest.
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
✓
Use a bucket policy to deny PutObject requests that do not include the x-amz-server-side-encryption header.
A bucket policy that denies PutObject requests lacking the `x-amz-server-side-encryption` header enforces encryption at the time of upload, ensuring that any object written without explicit encryption headers is rejected. Option E is correct because enabling default encryption on the S3 bucket automatically applies server-side encryption (SSE-S3 or SSE-KMS) to any object uploaded without specifying encryption headers, providing a fallback that covers all objects. Together, these actions ensure that every object stored in the bucket is encrypted at rest, either by explicit client request or by default bucket settings.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Enable S3 Versioning on the bucket.
Why it's wrong here
Versioning preserves prior object versions; it applies no encryption to object data at rest. It is tempting because versioning supports recovery and compliance retention, and would be the right choice when the requirement is to protect against accidental deletion or overwrites rather than to enforce encryption.
- ✗
Enable MFA Delete on the bucket.
Why it's wrong here
MFA Delete protects against accidental or malicious object deletion; it does not encrypt data at rest. It would be the correct control when the requirement is deletion protection, but here the mandated outcome is encryption, satisfied by default encryption or bucket policies.
- ✗
Configure S3 Access Points with network policies.
Why it's wrong here
S3 Access Points with network policies govern network access to buckets; they do not encrypt objects at rest. They would be the right choice when restricting access from specific VPCs, but the stated requirement is encryption, met through default encryption or bucket encryption policies.
- ✓
Use a bucket policy to deny PutObject requests that do not include the x-amz-server-side-encryption header.
Why this is correct
The bucket policy enforces encryption at upload time by rejecting any PutObject lacking the x-amz-server-side-encryption header, so unencrypted writes cannot succeed. This satisfies the requirement that all objects be encrypted at rest by preventing plaintext objects from ever being stored.
- ✓
Enable default encryption on the S3 bucket.
Why this is correct
Default bucket encryption automatically applies SSE to every object written, satisfying the requirement that all objects be encrypted at rest without relying on each uploader. It covers objects lacking explicit encryption headers, closing the gap left by request-based enforcement alone.
Quick reference
AWS S3 Storage Class Comparison
| Storage Class | Min Duration | Retrieval | Use Case |
|---|---|---|---|
| S3 Standard | None | Immediate | Frequently accessed data |
| S3 Standard-IA | 30 days | Immediate | Infrequent access, rapid retrieval |
| S3 One Zone-IA | 30 days | Immediate | Non-critical infrequent data |
| S3 Intelligent-Tiering | None | Immediate–hours | Unknown or changing access patterns |
| S3 Glacier Instant | 90 days | Milliseconds | Archive with instant retrieval |
| S3 Glacier Flexible | 90 days | Minutes–hours | Archive, flexible retrieval |
| S3 Glacier Deep Archive | 180 days | Hours | Long-term compliance archive |
Go deeper
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Same concept, more angles
1 more way this is tested on DEA-C01
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company uses Amazon S3 to store sensitive data. The security team wants to ensure that all objects uploaded to a specific S3 bucket are automatically encrypted at rest using server-side encryption with AWS KMS managed keys (SSE-KMS). Which bucket policy statement should be added to enforce this requirement?
medium- A.Deny put requests where 's3:x-amz-server-side-encryption' is 'aws:kms'
- ✓ B.Deny put requests where 's3:x-amz-server-side-encryption' is not 'aws:kms'
- C.Deny put requests where 's3:x-amz-server-side-encryption' is not 'AES256'
- D.Deny put requests where 's3:x-amz-server-side-encryption' is not set
Why B: It denies any S3 PUT request that does not include the `x-amz-server-side-encryption` header set to `aws:kms`, thereby enforcing SSE-KMS encryption for all objects uploaded to the bucket. This bucket policy condition ensures that only requests specifying AWS KMS-managed keys are allowed, meeting the security team's requirement for automatic encryption at rest with SSE-KMS.
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.