DEA-C01 Data Store Management Practice Question
A company uses Amazon S3 to store sensitive data. The security team requires that all data be encrypted at rest using a customer-managed key that is rotated annually. Which encryption option should be used?
⚠ Common exam trap
It's easy for candidates to confuse SSE-C with customer-managed keys, but SSE-C requires you to supply the key on every operation and does not support AWS-managed rotation, making it unsuitable for the 'rotated annually' requirement.
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
✓
SSE-KMS (Server-Side Encryption with AWS KMS).
SSE-KMS is the correct choice because it allows you to use a customer-managed key (CMK) in AWS KMS, which you can configure to rotate automatically on an annual schedule. This satisfies the security team's requirement for encryption at rest with a key you control and rotate yearly, while still leveraging server-side encryption that integrates with S3's existing infrastructure.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
SSE-KMS (Server-Side Encryption with AWS KMS).
Why this is correct
SSE-KMS encrypts objects at rest using keys held in AWS KMS, and supports customer-managed keys with automatic annual rotation. This satisfies the requirement for a customer-managed, annually rotated key, unlike SSE-S3, which uses AWS-managed keys that cannot be rotated on demand.
- ✗
SSE-S3 (Server-Side Encryption with S3-managed keys).
Why it's wrong here
SSE-S3 uses AWS-owned AES-256 keys, so the customer cannot manage, audit or rotate them annually, failing the customer-managed key requirement. It is tempting because it is the default, zero-effort encryption for S3 buckets, and would suffice where no key control or rotation policy is mandated.
- ✗
Client-side encryption.
Why it's wrong here
Client-side encryption happens before upload, so S3 never holds the key and cannot perform annual rotation; the customer manages keys entirely outside AWS. It suits scenarios demanding end-to-end confidentiality where AWS must never see plaintext or key material.
- ✗
SSE-C (Server-Side Encryption with Customer-Provided keys).
Why it's wrong here
SSE-C requires the customer to supply the encryption key on every request, and S3 stores only an HMAC to validate it, so S3 cannot rotate that key annually. SSE-C fits when you must retain sole possession of key material rather than delegate rotation to AWS KMS.
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
Related to this question
About these practice questions
One of 1,321 original DEA-C01 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
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.