A security team is concerned about data exfiltration. They want to ensure that a GKE cluster running a proprietary machine learning model can only…

VPC Service Controls is the required feature. It creates a security perimeter around Google-managed services to protect against data exfiltration. By placing the GKE cluster's project and the specific Cloud Storage bucket and BigQuery dataset within the same service perimeter, you can enforce a policy that allows communication only between resources inside this boundary. This control is context-aware and based on the network origin of the request, not just IAM permissions. Therefore, even if a service account token is compromised, an attacker cannot access services outside the perimeter from the compromised GKE cluster, effectively mitigating the exfiltration risk as described.

1. Google Cloud Documentation, "VPC Service Controls overview": In the "How VPC Service Controls works" section, it states, "VPC Service Controls helps mitigate data exfiltration risks... Even if a malicious actor gains access to credentials, such as from a compromised GKE pod, VPC Service Controls helps ensure that the services and data within the perimeter are not accessible from outside the perimeter."

2. Google Cloud Documentation, "Securing clusters with VPC Service Controls": This document explicitly details the use case in the question. The overview section states, "You can use VPC Service Controls with GKE to help protect your clusters... VPC Service Controls helps to prevent data exfiltration by allowing only authorized VPC networks or on-premises locations to access sensitive data in Google Cloud services."

3. Google Cloud Architecture Framework, "Security, privacy, and compliance," section on "Data exfiltration protection": This guide recommends VPC Service Controls as a primary mechanism. It states, "To mitigate the risk of data exfiltration, we recommend that you use VPC Service Controls. VPC Service Controls lets you define a service perimeter around your Google Cloud projects... Any communication between two services that are in the same perimeter is not restricted."