CCSP Cloud Platform and Infrastructure Security Practice Question
A healthcare organization stores PHI in an Amazon S3 bucket. An auditor finds that objects are encrypted with SSE-S3, and the organization wants to demonstrate that it controls the encryption keys and can audit their use independently of AWS-managed keys. Which change best satisfies this requirement while minimizing application changes?
⚠ Common exam trap
Test-takers frequently confuse 'customer controlled keys' with 'customer managed keys'; SSE-C gives control but shifts all key handling into the application, which is far more invasive than SSE-KMS.
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
✓
Switch the bucket to SSE-KMS using a customer managed key in AWS KMS, and grant the application role kms:Decrypt and kms:GenerateDataKey permissions.
SSE-KMS with a customer managed key allows the organization to define the key policy, control rotation, and audit every cryptographic operation through CloudTrail. Applications continue to use the standard S3 API with only additional IAM permissions on the KMS key, so code changes are minimal. This is the cleanest way to demonstrate independent key control and usage auditing.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Configure SSE-C with a customer-provided key sent on every request via the x-amz-server-side-encryption-customer-key header.
Why it's wrong here
SSE-C requires the application to supply the key on every PUT and GET request and to store and rotate the key itself, which increases code changes and operational burden. AWS does not retain the key, so there is no KMS-based usage audit trail. This does not meet the goal of minimizing application changes while providing auditable key control.
- ✓
Switch the bucket to SSE-KMS using a customer managed key in AWS KMS, and grant the application role kms:Decrypt and kms:GenerateDataKey permissions.
Why this is correct
SSE-KMS with a customer managed key gives the organization control over key policy, rotation, and usage auditing via CloudTrail, which directly satisfies the auditor's requirement. Applications continue to use the standard S3 API; only IAM permissions for the KMS key are added. This minimizes code changes while providing independent key control and auditability.
- ✗
Keep SSE-S3 but enable S3 Object Lock in compliance mode and versioning to prevent unauthorized key access.
Why it's wrong here
S3 Object Lock protects object immutability and retention; it does not give the organization control over encryption keys or provide key usage auditing. SSE-S3 keys remain AWS-managed and are not visible or auditable by the customer. This option addresses a different control objective entirely and does not satisfy the auditor's key-control requirement.
- ✗
Enable client-side encryption in the application using a locally stored AES-256 key and upload the encrypted objects to S3.
Why it's wrong here
Client-side encryption does give the organization full key control, but it requires significant application changes to encrypt and decrypt every object and to manage key distribution and rotation manually. It also removes S3's ability to perform server-side operations like range reads on encrypted objects. The requirement to minimize application changes makes this a poor fit compared to SSE-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
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About these practice questions
This CCSP question is part of Courseiva's 934-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam 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 ISC2 exam blueprint
This CCSP practice question is part of Courseiva's free ISC2 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 CCSP exam.