Google PCA Cloud External Key Manager (EKM) Practice Question
A healthcare organization is storing sensitive patient data in Cloud Storage. They need to ensure that all objects are encrypted with a key managed by their on-premises HSM. Which encryption approach should they use?
⚠ Common exam trap
In Google PCA, the trap here is that candidates confuse CMEK with EKM: CMEK keys are stored in Cloud KMS, not on an external HSM. EKM allows using an external key manager like an on-premises HSM.
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 Cloud External Key Manager (EKM) with a key hosted on the on-premises HSM.
Cloud External Key Manager (EKM) allows you to use an external key management system, such as an on-premises HSM, to manage encryption keys for Google Cloud services. This approach meets the requirement because the key never leaves the HSM, and Cloud Storage uses the key via the EKM integration, ensuring the organization retains full control over the key lifecycle.
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 Customer-Supplied Encryption Keys (CSEK) and store the key in a Secret Manager accessible only from the on-premises HSM.
Why it's wrong here
CSEK keys are supplied per request and never stored by Cloud Storage, so the service cannot decrypt objects for background operations or re-encryption, and the HSM cannot manage them at rest. CSEK suits clients holding keys entirely outside the cloud for strict per-object control.
- ✓
Use Cloud External Key Manager (EKM) with a key hosted on the on-premises HSM.
Why this is correct
Cloud External Key Manager lets Cloud Storage use a customer-managed key held in the on-premises HSM, so the key never leaves the organisation's hardware. This satisfies the requirement that encryption keys remain managed by the on-premises HSM.
- ✗
Use Customer-Managed Encryption Keys (CMEK) with a Cloud KMS key that is generated from the on-premises HSM.
Why it's wrong here
CMEK with Cloud KMS generates and stores key material inside Google's KMS, so the root key is not held by the on-premises HSM; importing wrapped material still leaves KMS managing it. CMEK is tempting for per-key rotation and IAM control, which fits organisations without an external key custodian.
- ✗
Encrypt each object client-side with a key from the on-premises HSM before uploading to Cloud Storage.
Why it's wrong here
Client-side encryption with an HSM key does keep key material on-premises, but Cloud Storage then holds only ciphertext, so the objects are not encrypted by the service with that key and features such as server-side re-encryption and integrity checking are lost. It suits data that must remain opaque to the provider.
Go deeper
Related to this question
Learn chapter
Billing, Budgets, and Cost Management
Key term
Cloud storage
Cloud storage is a service that lets you save data on remote servers accessed over the internet instead of on your computer's hard drive.
Key term
Organization
An Organization is a top-level container in Google Cloud that represents your company or entities and serves as the root node for all your cloud resources, policies, and access control.
About these practice questions
This PCA question is part of Courseiva's 807-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 by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCA practice question is part of Courseiva's free Google Cloud 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 PCA exam.