Question 55 of 1,738
Identity and Access ManagementmediumMultiple SelectObjective-mapped

Quick Answer

The correct answer is to create a VPC endpoint for Athena and attach a bucket policy that restricts access to that endpoint, combined with granting kms:Decrypt permission in the IAM policy while ensuring the KMS key policy allows the IAM role. This works because the VPC endpoint for Athena forces all query traffic through your specified subnets, and the S3 bucket policy uses the aws:SourceVpce condition to block any requests not originating from that endpoint, enforcing network isolation. For the encryption requirement, Athena must have explicit kms:Decrypt permission to read the encrypted S3 objects, and the KMS key policy must grant this permission to the IAM role assuming the Athena service. On the SCS-C02 exam, this question tests your understanding that s3:SourceIp is invalid for VPC endpoints—a common trap—and that SSE-S3 default encryption bypasses KMS entirely. Remember the memory tip: “Endpoint for network, KMS for decrypt—never mix SourceIp with a VPCe.”

SCS-C02 Identity and Access Management Practice Question

This SCS-C02 practice question tests your understanding of identity and access management. 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 security engineer is designing IAM policies for a data analytics platform that uses Amazon S3, Amazon Athena, and AWS Glue. The platform must allow data scientists to query data in S3 using Athena, but only from specific VPC subnets. Additionally, the data must be encrypted at rest using AWS KMS. Which TWO actions should the engineer take to meet these requirements? (Choose TWO.)

Question 1mediummulti select
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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

Grant kms:Decrypt permission in the IAM policy and configure the KMS key policy to allow the IAM role to use the key.

A: Correct – Using a VPC endpoint for Athena with a bucket policy that restricts access to the VPC endpoint ensures that queries are only allowed from the specified VPC subnets. D: Correct – Granting kms:Decrypt permission in the IAM policy and ensuring the KMS key policy allows the IAM role enables Athena to decrypt S3 objects encrypted with a customer-managed KMS key. B: Incorrect – The s3:SourceIp condition key does not work for VPC endpoints; use aws:SourceVpce instead. C: Incorrect – The kms:EncryptionContext condition is not used for restricting encryption at rest; it is used for encryption context in KMS operations. E: Incorrect – S3 default encryption (SSE-S3) does not use KMS, so the KMS key policy would not be relevant.

Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Grant kms:Decrypt permission in the IAM policy and configure the KMS key policy to allow the IAM role to use the key.

    Why this is correct

    Correct – Allows Athena to decrypt S3 objects with the KMS key.

    Related concept

    CIDR notation defines the prefix length.

  • Add kms:EncryptionContext condition to the IAM policy to require a specific encryption context.

    Why it's wrong here

    Incorrect – Encryption context is not used for restricting encryption at rest.

  • Create a VPC endpoint for Athena and attach a bucket policy that restricts access to that endpoint.

    Why this is correct

    Correct – Restricts Athena queries to the VPC endpoint.

    Related concept

    CIDR notation defines the prefix length.

  • Use the s3:SourceIp condition key in the IAM policy to restrict access to the private IP ranges of the VPC subnets.

    Why it's wrong here

    Incorrect – s3:SourceIp does not work with VPC endpoints; use aws:SourceVpce.

  • Enable default encryption on the S3 bucket using SSE-S3 and configure the KMS key policy to allow the IAM role.

    Why it's wrong here

    Incorrect – SSE-S3 does not use KMS; the key policy would not be needed.

Common exam traps

Common exam trap: usable hosts are not the same as total addresses

Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.

Detailed technical explanation

How to think about this question

Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.

KKey Concepts to Remember

  • CIDR notation defines the prefix length.
  • Block size helps identify subnet boundaries.
  • Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
  • The required host count determines the smallest suitable subnet.

TExam Day Tips

  • Write the block size before choosing the subnet.
  • Check whether the question asks for hosts, subnets or a specific address range.
  • Do not confuse /24, /25, /26 and /27 host counts.

Key takeaway

Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

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.

Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related SCS-C02 subnetting questions on CIDR, address ranges, and subnet selection.

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FAQ

Questions learners often ask

What does this SCS-C02 question test?

Identity and Access Management — This question tests Identity and Access Management — CIDR notation defines the prefix length..

What is the correct answer to this question?

The correct answer is: Grant kms:Decrypt permission in the IAM policy and configure the KMS key policy to allow the IAM role to use the key. — A: Correct – Using a VPC endpoint for Athena with a bucket policy that restricts access to the VPC endpoint ensures that queries are only allowed from the specified VPC subnets. D: Correct – Granting kms:Decrypt permission in the IAM policy and ensuring the KMS key policy allows the IAM role enables Athena to decrypt S3 objects encrypted with a customer-managed KMS key. B: Incorrect – The s3:SourceIp condition key does not work for VPC endpoints; use aws:SourceVpce instead. C: Incorrect – The kms:EncryptionContext condition is not used for restricting encryption at rest; it is used for encryption context in KMS operations. E: Incorrect – S3 default encryption (SSE-S3) does not use KMS, so the KMS key policy would not be relevant.

What should I do if I get this SCS-C02 question wrong?

Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related SCS-C02 subnetting questions on CIDR, address ranges, and subnet selection.

What is the key concept behind this question?

CIDR notation defines the prefix length.

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Last reviewed: Jun 20, 2026

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This SCS-C02 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 SCS-C02 exam.