The correct answer is to use SSE-KMS with a customer-managed key (CMK), as this is the only S3 encryption option that combines AWS KMS encryption at rest with support for automatic key rotation. A customer-managed CMK allows you to enable annual automatic key rotation, which satisfies the security policy requirement, whereas AWS managed keys do not support automatic rotation and SSE-C bypasses KMS entirely. On the AWS Certified Data Engineer Associate DEA-C01 exam, this question tests your understanding of the nuanced differences between KMS key types and their rotation capabilities—a common trap is assuming all KMS keys rotate automatically. Remember that only customer-managed CMKs offer the option to enable automatic rotation; AWS managed keys and SSE-C are non-compliant here. Memory tip: “CMK = Can Manage Key rotation,” while AWS managed keys are “Always Managed, never Auto-rotated.”
DEA-C01 Data Security and Governance Practice Question
This DEA-C01 practice question tests your understanding of data security and governance. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 is designing a data lake on Amazon S3. The security policy requires that all data be encrypted at rest using AWS KMS with automatic key rotation. Which encryption option meets these requirements? (Select THREE.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Enable automatic key rotation on the KMS key.
Option A is correct because AWS KMS customer-managed keys (CMKs) support automatic key rotation, which can be enabled to rotate the key material annually. This satisfies the security policy requirement for automatic key rotation. SSE-KMS with a CMK (Option D) is also required because AWS managed keys (Option B) do not support automatic key rotation, and SSE-C (Option E) does not use KMS at all. Setting default encryption on the S3 bucket to SSE-KMS with the CMK (Option C) ensures all objects are encrypted with that key, meeting the encryption-at-rest requirement.
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.
✓
Enable automatic key rotation on the KMS key.
Why this is correct
This is a requirement.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use SSE-KMS with an AWS managed key.
Why it's wrong here
AWS managed keys do not support automatic rotation.
✓
Set the default encryption on the S3 bucket to SSE-KMS with the CMK.
Why this is correct
This ensures all objects are encrypted.
Related concept
Read the scenario before looking for a memorised answer.
✓
Use SSE-KMS with a customer-managed key (CMK).
Why this is correct
CMKs support automatic rotation.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use SSE-C with a customer-provided key.
Why it's wrong here
SSE-C does not support key rotation.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often assume AWS managed keys (aws/s3) support automatic key rotation, but they do not; only customer-managed CMKs allow you to enable automatic rotation, and the question requires selecting three correct options that together meet both the KMS and automatic rotation requirements.
Detailed technical explanation
How to think about this question
AWS KMS automatic key rotation for customer-managed CMKs rotates the backing key annually, but the key ID, ARN, and metadata remain unchanged, so existing encrypted data remains decryptable. Under the hood, KMS creates new backing key versions while retaining old ones, enabling seamless re-encryption of new data. In a real-world scenario, if the policy requires compliance with standards like PCI DSS or SOC 2, automatic key rotation is often mandatory, and using SSE-KMS with a CMK allows the organization to meet audit requirements while maintaining control over the key lifecycle.
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 media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
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.
Data Security and Governance — This question tests Data Security and Governance — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Enable automatic key rotation on the KMS key. — Option A is correct because AWS KMS customer-managed keys (CMKs) support automatic key rotation, which can be enabled to rotate the key material annually. This satisfies the security policy requirement for automatic key rotation. SSE-KMS with a CMK (Option D) is also required because AWS managed keys (Option B) do not support automatic key rotation, and SSE-C (Option E) does not use KMS at all. Setting default encryption on the S3 bucket to SSE-KMS with the CMK (Option C) ensures all objects are encrypted with that key, meeting the encryption-at-rest requirement.
What should I do if I get this DEA-C01 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 →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This DEA-C01 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 DEA-C01 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.