The answer is a symmetric key with an automatic rotation period set to 90 days. This works because Cloud KMS uses key versions; when automatic rotation is enabled, the service creates a new primary key version at the specified interval while retaining older versions for decryption. Since the key material is never exposed to users, existing ciphertext remains decryptable by its original key version, eliminating any need for re-encryption. On the Google Professional Cloud Security Engineer exam, this scenario tests your understanding that symmetric keys are used for data-at-rest encryption and that automatic rotation is a versioning operation, not a key replacement—a common trap is assuming rotation forces data re-encryption. Remember the mnemonic: "Rotate the version, not the data."
PCSE Ensuring data protection Practice Question
This PCSE practice question tests your understanding of ensuring data protection. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company uses Cloud KMS to protect encryption keys for various applications. They need to ensure that keys are automatically rotated every 90 days and that the rotation does not require re-encrypting all data. Which key type and rotation strategy should they use?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use a symmetric key with automatic rotation period set to 90 days.
Symmetric keys are used for encryption/decryption of data at rest, and Cloud KMS supports automatic key rotation by creating a new key version at a specified interval (e.g., 90 days). Because Cloud KMS uses key versions and the key material is never exposed, existing ciphertext remains decryptable using the old key version, so no re-encryption is required. This meets the requirement for automatic rotation without data re-encryption.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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 a symmetric key with automatic rotation period set to 90 days.
Why this is correct
Symmetric keys support automatic rotation, and old versions remain for decryption.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use an asymmetric key and set the rotation period to 90 days.
Why it's wrong here
Cloud KMS does not support automatic rotation for asymmetric keys.
✗
Use an asymmetric key and manually create a new version every 90 days.
Why it's wrong here
Asymmetric keys lack automatic rotation, and manual effort is required.
✗
Use a symmetric key and manually create a new version every 90 days.
Why it's wrong here
Manual rotation is not automated and prone to error.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Google Cloud often tests the misconception that automatic rotation requires re-encrypting data, or that asymmetric keys are suitable for bulk encryption, leading candidates to choose manual rotation or asymmetric key options.
Detailed technical explanation
How to think about this question
Cloud KMS symmetric keys use a key ring and key version model where each version has a unique key material and an associated state (enabled, disabled, destroyed). When automatic rotation is enabled, Cloud KMS creates a new primary key version at the specified interval, and the old primary version remains available for decryption of existing data. The rotation period is defined in seconds (e.g., 90 days = 7,776,000 seconds) and can be set at key creation or updated later. This design ensures that data encrypted with older versions can still be decrypted without re-encryption, as long as the old key version is not destroyed.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Ensuring data protection — This question tests Ensuring data protection — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use a symmetric key with automatic rotation period set to 90 days. — Symmetric keys are used for encryption/decryption of data at rest, and Cloud KMS supports automatic key rotation by creating a new key version at a specified interval (e.g., 90 days). Because Cloud KMS uses key versions and the key material is never exposed, existing ciphertext remains decryptable using the old key version, so no re-encryption is required. This meets the requirement for automatic rotation without data re-encryption.
What should I do if I get this PCSE question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Refer to the exhibit. Based on the exhibit, the corporate security policy requires that all Cloud KMS symmetric keys have automatic rotation enabled. Which statement is true?
hard
A.Both keys are compliant.
B.Neither key is compliant.
✓ C.Only the encryption-key is compliant.
D.Only the decryption-key is compliant.
Why C: The corporate security policy requires automatic rotation for all Cloud KMS symmetric keys. In the exhibit, the 'encryption-key' has automatic rotation enabled (as indicated by the rotation period being set), while the 'decryption-key' does not have automatic rotation enabled (rotation period is not set or is disabled). Therefore, only the encryption-key is compliant with the policy.
Last reviewed: Jun 30, 2026
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This PCSE 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 PCSE exam.
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