The answer is that the object was encrypted with SSE-S3, which violates the bucket policy. This is correct because the bucket policy explicitly requires all objects to be encrypted with SSE-KMS, meaning any PutObject request must include the `x-amz-server-side-encryption` header set to `aws:kms` and a valid KMS key identifier. When CloudTrail logs show a successful PutObject event but the encryption context reveals SSE-S3, the request technically succeeded from a storage perspective but failed to meet the policy condition, resulting in a policy violation rather than a denied request. On the AWS Certified Data Engineer Associate DEA-C01 exam, this scenario tests your ability to differentiate between encryption methods in S3 bucket policies and to interpret CloudTrail logs for compliance, a common trap being that a successful HTTP status code does not guarantee policy adherence. Remember the key distinction: SSE-S3 uses Amazon-managed keys, while SSE-KMS requires customer-managed KMS keys—if the policy says “KMS,” any other encryption is a violation.
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.
Refer to the exhibit. A security analyst is reviewing CloudTrail logs and notices a PutObject event to the 'company-data-lake' bucket. The bucket policy requires all objects to be encrypted with SSE-KMS. What should the analyst conclude?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The object was encrypted with SSE-S3, which violates the bucket policy.
The bucket policy requires all objects to be encrypted with SSE-KMS. The CloudTrail log shows a PutObject event, but the encryption context (not shown in the exhibit) would indicate the encryption method used. Since the correct answer states the object was encrypted with SSE-S3, this violates the bucket policy, which mandates SSE-KMS. Therefore, the analyst should conclude that the request succeeded but violated the policy, as SSE-S3 does not meet the 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.
✗
The object was uploaded by the bucket owner, bypassing the policy.
Why it's wrong here
The policy applies to all principals.
✗
The request succeeded because SSE-S3 is acceptable.
Why it's wrong here
The bucket policy requires SSE-KMS, so the request should be denied.
✗
The object was encrypted with SSE-KMS as required.
Why it's wrong here
The encryption header shows AES256, which is SSE-S3.
✓
The object was encrypted with SSE-S3, which violates the bucket policy.
Why this is correct
AES256 indicates SSE-S3, not KMS.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
AWS often tests the nuance that a bucket policy requiring SSE-KMS does not automatically deny requests using SSE-S3; the policy must include an explicit Deny effect for non-compliant encryption to block the upload, so candidates may mistakenly think a requirement alone prevents the action.
Trap categories for this question
Command / output trap
The encryption header shows AES256, which is SSE-S3.
Detailed technical explanation
How to think about this question
SSE-KMS uses AWS KMS to manage encryption keys, providing additional control and auditability via key policies and CloudTrail key usage events. In contrast, SSE-S3 uses Amazon S3-managed keys (AES-256) and does not allow the same level of granular control. A bucket policy can enforce SSE-KMS using a condition like `s3:x-amz-server-side-encryption: aws:kms`, and if the request uses SSE-S3 instead, the policy evaluation will fail the condition, but the request may still succeed if the policy is not explicitly denying it—this is a common misconfiguration where the policy only requires SSE-KMS but does not deny other encryption methods, leading to a successful but non-compliant upload.
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: The object was encrypted with SSE-S3, which violates the bucket policy. — The bucket policy requires all objects to be encrypted with SSE-KMS. The CloudTrail log shows a PutObject event, but the encryption context (not shown in the exhibit) would indicate the encryption method used. Since the correct answer states the object was encrypted with SSE-S3, this violates the bucket policy, which mandates SSE-KMS. Therefore, the analyst should conclude that the request succeeded but violated the policy, as SSE-S3 does not meet the 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 →
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. A data engineer applies the following S3 bucket policy to an S3 bucket. What does this policy enforce?
medium
A.Denies all uploads unless SSE-S3 is used
B.Allows only SSE-S3 encrypted uploads
C.Allows any type of server-side encryption
✓ D.Requires that all objects uploaded to the bucket be encrypted with SSE-KMS
Why D: The policy denies s3:PutObject if the object is not encrypted with SSE-KMS. Option A is wrong because it denies if not SSE-KMS, not allows only SSE-S3. Option B is wrong because it doesn't require SSE-S3. Option D is wrong because it doesn't allow any encryption. Option C is correct.
Variation 2. Refer to the exhibit. A data engineer applies this S3 bucket policy to the bucket 'example-bucket'. What is the effect of this policy?
easy
✓ A.PutObject requests are denied unless they include the x-amz-server-side-encryption header set to AES256
B.All PutObject requests are denied regardless of encryption
C.All PutObject requests are allowed only if they use SSE-KMS
D.The policy has no effect because it does not allow any action
Why A: The policy denies s3:PutObject if the encryption header is not set to AES256 (SSE-S3). It does not enforce a specific KMS key. It allows uploads with SSE-S3. It denies uploads without encryption or with other encryption types.
Variation 3. Refer to the exhibit. A data engineer attached this S3 bucket policy to the bucket 'example-bucket'. What is the effect of this policy?
hard
A.It allows all PutObject requests that do not use encryption
✓ B.It denies PutObject requests that do not use SSE-S3
C.It denies all PutObject requests unless they use SSE-KMS
D.It denies all PutObject requests from anonymous users
Why B: Option C is correct. The policy denies PutObject if the request does not use SSE-S3 (AES256). Option A is wrong because it does not enforce SSE-KMS. Option B is wrong because it allows requests with SSE-S3. Option D is wrong because it does not deny all requests.
Last reviewed: Jun 30, 2026
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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.
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