An organization wants to ensure that all their critical S3 buckets are encrypted with keys that only they physically possess in an on-premises HSM. Which KMS feature allows you to use your own HSM as the back-end for KMS encryption?

Direct Answer (Verified)Reviewed by Sunny (Senior Cloud Engineer)

Correct Answer: KMS External Key Store (XKS)

XKS allows AWS KMS to use a key store located outside of AWS (like your on-prem HSM), providing the highest level of cryptographic control....

📋Part of AWS Certified Solutions Architect – Professional (SAP-C02) · AWS Certification Practice
Real Exam ScenarioAWS KMS

An organization wants to ensure that all their critical S3 buckets are encrypted with keys that only they physically possess in an on-premises HSM. Which KMS feature allows you to use your own HSM as the back-end for KMS encryption?

✓ Correct Answer & ExplanationAWS KMS

Correct Answer

KMS External Key Store (XKS)

Why This Answer Is Correct

XKS allows AWS KMS to use a key store located outside of AWS (like your on-prem HSM), providing the highest level of cryptographic control.

📚 What This Question Tests

This question evaluates your knowledge of AWS KMS — a core concept tested in AWS Certified Solutions Architect – Professional (SAP-C02). Understanding AWS KMS is essential for designing scalable, secure, and cost-effective cloud architectures. Mastery of this topic will help you answer scenario-based questions confidently on exam day.