Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
A company has an S3 bucket that stores sensitive data. The data is encrypted at rest using an AWS KMS customer managed key (CMK). The security team wants to ensure that only a specific IAM role in the same account can decrypt the objects. Which configuration should the developer implement?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
Add a bucket policy that denies s3:GetObject unless the request uses a specific IAM role.
Bucket policies control S3 access, not KMS decryption permissions.
B
Best answer
Add a key policy that allows the IAM role to perform kms:Decrypt and denies all other principals.
KMS access is controlled via key policies; this grants decryption only to the specified role.
C
Distractor review
Configure the S3 bucket with default encryption using the KMS key.
Default encryption ensures encryption but does not restrict which principals can decrypt.
D
Distractor review
Create an IAM policy that grants kms:Decrypt only to the specific role.
Without a key policy allowing IAM access, the IAM policy alone is not sufficient.
Common exam trap
Common exam trap: ACLs stop at the first match
ACLs are processed top to bottom. The first matching entry wins, and an implicit deny usually exists at the end.
Technical deep dive
How to think about this question
ACL questions test precision: source, destination, protocol, port and direction. A generally correct ACL can still fail if it is applied on the wrong interface or in the wrong direction.
KKey Concepts to Remember
- Standard ACLs match source addresses.
- Extended ACLs can match source, destination, protocol and ports.
- The first matching ACL entry is used.
- There is usually an implicit deny at the end.
TExam Day Tips
- Check inbound versus outbound direction.
- Read the ACL from top to bottom.
- Look for a broader permit or deny above the intended line.
Related practice questions
Related DVA-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A developer is building a REST API using Amazon API Gateway that will serve static content from an Amazon S3 bucket. The API should cache responses for frequently accessed objects to reduce latency. Which API Gateway feature should the developer enable?
Question 2
A developer is running a web application on multiple Amazon EC2 instances behind an Application Load Balancer (ALB). The application needs to store user session state that must be available across all instances. The session data is small and temporary but must survive individual instance failures. Which AWS service should the developer use to store this session state?
Question 3
A developer has an AWS Lambda function that processes messages from an Amazon SQS standard queue. The function is idempotent and currently has a batch size of 10. The developer wants to increase throughput and increases the batch size to 100. After the change, CloudWatch metrics show a significant increase in throttles and the queue backlog is growing. The function's reserved concurrency is set to 10. What is the most effective action to resolve the throttling and improve throughput?
Question 4
A developer is managing an application running on Amazon EC2 instances behind an Application Load Balancer. Users report that the application becomes unresponsive after several hours, and restarting the instance temporarily fixes the issue. The developer suspects a memory leak but cannot add custom instrumentation. Which AWS service can collect memory utilization metrics and help identify the memory leak with minimal configuration?
Question 5
A developer is building a serverless web application using AWS Lambda and Amazon DynamoDB. The application needs to perform complex aggregations on data stored in DynamoDB. Which AWS service should the developer use to perform these aggregations efficiently without reading all the data into Lambda?
Question 6
A developer has an Amazon S3 bucket containing private user documents. The application must generate a time-limited URL for users to download their own documents without requiring the users to have AWS credentials. Which solution should the developer use?
FAQ
Questions learners often ask
What does this DVA-C02 question test?
Standard ACLs match source addresses.
What is the correct answer to this question?
The correct answer is: Add a key policy that allows the IAM role to perform kms:Decrypt and denies all other principals. — KMS access is governed by key policies, not IAM policies alone. To restrict decryption to a specific role, the key policy must grant the kms:Decrypt action to that role and deny it to all other principals. An IAM policy alone is insufficient because KMS requires an explicit allow in the key policy. S3 bucket policies and default encryption do not control access to the KMS key.
What should I do if I get this DVA-C02 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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