SAA-C03 Design Secure Architectures Practice Question
A company stores sensitive customer data in an Amazon S3 bucket. The security team wants to ensure that all data is encrypted at rest using keys that the company controls, including the ability to rotate keys and audit key usage. They also want to minimize operational overhead for key management. Which solution meets these requirements?
⚠ Common exam trap
The trap here is assuming that any server-side encryption provides customer-controlled keys and auditability.
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 S3 server-side encryption with AWS KMS customer managed keys (SSE-KMS).
SSE-KMS with customer managed keys allows the company to control the KMS keys, configure automatic rotation, and audit key usage through CloudTrail. It is a native S3 feature, so no application changes are needed. SSE-S3 does not give key control, SSE-C requires the customer to manage keys per request, and client-side encryption adds significant operational burden.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Use S3 server-side encryption with AWS KMS customer managed keys (SSE-KMS).
Why this is correct
SSE-KMS with customer managed keys gives the company control over the KMS key, including key policies, rotation, and auditing via AWS CloudTrail. It integrates natively with S3, so no application changes are needed, minimizing operational overhead. This meets the requirements for customer-controlled keys, rotation, and auditability while leveraging AWS-managed infrastructure.
- ✗
Use S3 server-side encryption with customer-provided keys (SSE-C).
Why it's wrong here
SSE-C requires the company to provide and manage its own encryption keys with every request, and AWS does not store the keys. This increases operational overhead because the application must handle key storage and rotation. It also does not provide the same level of auditability through CloudTrail as KMS. The requirement to minimize operational overhead is not met.
- ✗
Use S3 server-side encryption with Amazon S3 managed keys (SSE-S3).
Why it's wrong here
SSE-S3 uses keys managed entirely by Amazon S3, so the company does not control the keys and cannot audit their usage or manage rotation policies. While it encrypts data at rest, it does not provide the customer-controlled key management and auditability required. The security team's requirement for control over keys and rotation is not satisfied by SSE-S3.
- ✗
Encrypt the data client-side before uploading to S3 using an open-source library, and store the keys in AWS Secrets Manager.
Why it's wrong here
Client-side encryption gives full control but requires significant application changes, key management, and rotation logic, which increases operational overhead. While Secrets Manager can store keys, integrating it with client-side encryption and ensuring auditability requires custom code. This does not minimize operational overhead compared to a native S3 encryption option with 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
Courseiva writes every SAA-C03 question from scratch — 935 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Amazon Web Services exam blueprint
This SAA-C03 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 SAA-C03 exam.