An enterprise is deploying an AI agent solution built on the Gemini platform on Google Cloud. The architecture processes real-time user prompts, retrieves context from backend storage, and persists conversation history and model outputs. The security team mandates the following compliance and data governance requirements: Data Residency and Sovereignty: All prompt inputs, model outputs, and training datasets (at rest, in use, and in transit) must strictly remain within the europe-west1 region and be prevented from crossing virtual network boundaries. In-flight Data Governance: Sensitive data within user prompts and agent responses must be classified and de-identified synchronously in real time before persistence. Cryptographic Control: All stored data must be encrypted with Customer-Managed Encryption Keys (CMEK) rooted in the same geographic region. Which combination of security controls should the security engineer implement?

Configure real-time prompt and output sanitization using the Cloud DLP synchronous `content.deidentify` method targeting the `dlp.europe-west1.rep.googleapis.com` regional endpoint; enforce the `constraints/gcp.restrictEndpointUsage` and `constraints/gcp.resourceLocations` organization policies; enclose services within a VPC Service Controls perimeter; and configure CMEK using Cloud KMS keys created in `europe-west1`.: What the solution is This architecture combines Sensitive Data Protection (Cloud DLP) regional endpoints, VPC Service Controls, Cloud KMS, and Organization Policy Service constraints to establish end-to-end data governance, strict data residency, and encryption for AI workloads. How it meets all requirements In-flight Data Governance: The synchronous content.deidentify API method of Cloud DLP inspects and de-identifies prompt strings and model responses in real time before data reaches persistent backend storage. Data Residency and In-Transit Sovereignty: Calling the regional endpoint dlp.europe-west1.rep.googleapis.com ensures that TLS sessions terminate inside europe-west1, guaranteeing that data at rest, in use, and in transit never leaves the specified region. Enforcing constraints/gcp.restrictEndpointUsage prevents client calls from accidentally routing to global endpoints. Resource Location Enforcement: Enforcing constraints/gcp.resourceLocations limits resource provisioning strictly to europe-west1 across all projects. Perimeter Isolation: VPC Service Controls defines a security perimeter around storage, AI APIs, and database services, preventing unauthorized exfiltration and ingress across project boundaries. Cryptographic Control: CMEK keys provisioned via Cloud KMS in europe-west1 wrap local data encryption keys (DEKs) ensuring full customer control over encryption at rest. Key advantages and capabilities Zero Regional Spillover: Regional API endpoints prevent traffic from terminating at Google's global points of presence outside the sovereign boundary. Synchronous Protection: Inline masking with content methods sanitizes generative AI inputs and outputs before storage. Defense-in-Depth: Combines network perimeters (VPC-SC), resource placement constraints, cryptographic controls (CMEK), and payload inspection.