Amazon Web Services SCS-C03 Online Access

SSE-S3 uses AWS-managed keys and does not provide customer control. AWS Certified Security – Specialty documentation states that SSE-KMS with customer managed keys allows full control, auditing, and key rotation. The security engineer must first create a customer managed KMS key, then update the bucket to use SSE-KMS. Existing objects must be re-encrypted to ensure compliance.

SSE-C requires the application to manage keys, increasing complexity and risk. AWS managed keys do not meet the requirement for customer-controlled encryption.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon S3 Encryption Options

AWS KMS Customer Managed Keys

Amazon S3 Lifecycle rules provide anative, fully managed mechanismto automatically transition or delete objects based on their age. According to the AWS Certified Security – Specialty Official Study Guide, S3 Lifecycle policies are therecommended and most secure methodfor enforcing data retention requirements because they operate automatically, consistently, and without custom code.

By configuring a lifecycle rule to delete objects after 45 days, the company ensures that sensitive datasets are retained long enough to support the 30-day model training process while remaining compliant with the data retention policy. Lifecycle rules are enforced by Amazon S3 itself and apply uniformly to all objects in the bucket or to objects that match specific prefixes or tags.

Option B and Option C introduce unnecessary operational complexity and risk by relying on custom Lambda code and scheduling. These approaches are more error-prone, harder to audit, and less reliable than a built-in S3 capability. Option D is incorrect because S3 Intelligent-Tiering manages storage cost optimization and does not delete data.

AWS documentation explicitly states thatS3 Lifecycle rules are the standard control for enforcing retention and deletion policies, particularly for sensitive data stored at scale.

AWS Certified Security – Specialty Official Study Guide

Amazon S3 Lifecycle Configuration Documentation

AWS Data Protection Best Practices

To restrict activity to a single Region in an OU using an SCP, the standard pattern is an explicitDenyfor requests madeoutsidethe allowed Region, while carving out exceptions forglobal servicesthat do not use aws:RequestedRegion in the same way (or that must remain usable regardless of Region). This is done withEffect: Deny, aConditionusing StringNotEquals on aws:RequestedRegion for the allowed Region (here, eu-west-1), andNotActionlisting the global services that should remain available.

This works because SCPs act asguardrails: an explicit Deny in an SCP overrides IAM Allow in member accounts, ensuring the restriction applies consistently to all existing and future accounts placed in the OU. The StringNotEquals condition ensures the deny triggers for any Region other than eu-west-1. The NotAction exception list ensures that the specified global services are not blocked by this deny statement.

Option A is wrong because StringEquals would deny actionsineu-west-1 rather than outside it. Options B and D useAllowstatements, which do not enforce “only this Region” safely in SCPs unless combined with a comprehensive deny strategy; they would not reliably restrict all other services/regions. Therefore, option C is the correct SCP structure.

AWS CloudTrail provides a record of all API calls made in an AWS account, including calls initiated by AWS CloudFormation. According to the AWS Certified Security – Specialty Study Guide, CloudTrail is the primary source for troubleshooting authorization failures because it records denied actions and the policy type that caused the denial, including service control policies.

Reviewing CloudTrail logs allows a security engineer to identify which specific API calls failed during the CloudFormation deployment and whether the denial was caused by an SCP, an IAM policy, or a permission boundary. This evidence-based approach is the recommended first step before making any configuration changes.

Option B is unsafe and violates governance best practices by removing SCPs in production. Option C may be necessary later, but it does not identify whether SCPs are the root cause. Option D introduces unnecessary risk and bypasses the purpose of differentiated controls across OUs.

AWS documentation emphasizes observing and validating before modifying security controls, making CloudTrail log analysis the correct initial troubleshooting step.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS Organizations Service Control Policies

AWS CloudTrail Authorization Failure Analysis