SCS-C02 Infrastructure Security Practice Question
A company wants to encrypt data at rest in an Amazon RDS for MySQL DB instance. Which AWS service or feature should be used to achieve this?
⚠ Common exam trap
Test-takers frequently confuse the RDS encryption feature (which is a checkbox in the console) with a standalone service, when in fact the underlying service that performs the encryption and key management is AWS 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
✓
AWS Key Management Service (KMS)
AWS Key Management Service (KMS) is the correct service because Amazon RDS for MySQL uses KMS-managed customer master keys (CMKs) to enable encryption at rest for DB instances. When you enable RDS encryption, RDS automatically integrates with KMS to encrypt the underlying storage, automated backups, read replicas, and snapshots using AES-256 encryption. This is the foundational service that provides the key management and encryption operations for RDS at-rest 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.
- ✓
AWS Key Management Service (KMS)
Why this is correct
KMS provides encryption keys for RDS encryption.
- ✗
Amazon S3 server-side encryption
Why it's wrong here
S3 server-side encryption is for S3 objects, not RDS.
- ✗
RDS encryption feature
Why it's wrong here
RDS encryption uses KMS, but the question asks for the service.
- ✗
SSL/TLS certificates
Why it's wrong here
SSL/TLS encrypts data in transit, not at rest.
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 |
Go deeper
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SCS-C02 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 SCS-C02 exam.