This PD and bucket data is encrypted using a Google-generated data encryption key (DEK) and key encryption key (KEK). The CMEK feature allows you to create, use, and revoke the key encryption key (KEK). Google still controls the data encryption key (DEK). For more information on Google data encryption keys, see Encryption at Rest. https://cloud.google.com/dataproc/docs/concepts/configuring-clusters/customer- managed-encryption
https://codelabs.developers.google.com/codelabs/encrypt-and-decrypt-data-with-cloud-kms#0

To ensure that PII data is separated from non-PII data, using Cloud Pub/Sub and Cloud Functions to trigger a scan by the Data Loss Prevention (DLP) API is an effective approach. This method allows for automated detection and handling of PII.
Steps:
* Set Up Cloud Pub/Sub: Configure a Cloud Pub/Sub topic to receive notifications whenever a file is uploaded to the shared Cloud Storage bucket.
* Deploy Cloud Functions: Create a Cloud Function that is triggered by the Pub/Sub topic. This function will invoke the DLP API to scan the uploaded file for PII.
* Move Detected PII Files: If the scan detects PII, the Cloud Function will move the file to a secure Cloud Storage bucket accessible only by the administrator.
* Set Permissions: Ensure that appropriate permissions are set on the Cloud Storage buckets to restrict access to files containing PII.
References:
* Google Cloud: Data Loss Prevention
* Cloud Functions documentation

https://cloud.google.com/sql/docs/mysql/cmek
"You might have situations where you want to permanently destroy data encrypted with CMEK. To do this, you destroy the customer-managed encryption key version. You can't destroy the keyring or key, but you can destroy key versions of the key."

To investigate and remediate the issue of public access to Cloud Storage buckets, you can follow these steps:
Change Bucket Permissions:
Navigate to the Cloud Storage section in the Google Cloud Console.
For each affected bucket, remove any public access permissions (e.g., removing allUsers or allAuthenticatedUsers from the IAM policy).
Ensure that only authorized users have the necessary permissions to access the buckets.
Query Data Access Audit Logs:
Go to the Logging section in the Google Cloud Console.
Query the audit logs for the affected buckets to identify any unauthorized access. You can use filters to search for access by unauthorized users.
Correct the Misconfiguration:
After correcting the permissions, mute the relevant findings in the Security Command Center to indicate that the issue has been resolved.
This helps in maintaining a clear view of ongoing security issues and ensures the findings are not flagged again unless there's a new occurrence.
By following these steps, you ensure that the buckets are no longer publicly accessible, investigate any potential unauthorized access, and update the Security Command Center status to reflect the resolution of the issue.
Cloud Storage IAM Permissions
Viewing Audit Logs
Security Command Center Documentation

Comprehensive and Detailed Explanation From Exact Extract:
The key requirements are maintaining a specific set of controls, including data residency and personnel data access controls, specifically to meet a highly regulated industry's compliance program.
Assured Workloads is the specific Google Cloud service designed to help customers meet these stringent regulatory and compliance requirements (e.g., FINRA, FedRAMP, HIPAA, etc.) by enforcing a specific control bundle.
Extracts:
"Assured Workloads helps organizations run their sensitive workloads securely and in a compliant manner...
by providing continuous compliance monitoring for specific compliance programs." (Source 4.1)
"When you create an Assured Workloads folder, the platform automatically enforces compliance controls...
including: Data residency and location controls... Personnel access controls... Organizational policies..." (Source 4.2) This service creates a dedicated, compliant environment in a folder, ensuring the necessary configurations and personnel controls are applied automatically and continuously maintained, which is a more complete solution than the posture management in option B (which focuses only on configuration monitoring) or the singular organizational policy in option C.