Google shows how to build zero-trust AI agents with ADK, using three hard security layers against prompt injection

用 Google 的 Agent Development Kit 构建零信任 AI 智能体

Google's developer blog open-sourced a customer support refund agent to show why system prompts aren't security boundaries. A single prompt injection can bypass refund caps or leak environment variables. The fix is three hard layers: every database write is signed with a Cloud KMS hardware-backed key, dynamically generated code runs inside a gVisor sandbox with no network egress, and all I/O passes through deterministic semantic gateways. Full code and a local demo using HMAC to simulate KMS are on GitHub.

Why it matters: Google's official blog drops a practical ADK security architecture walkthrough, demoing prompt injection on a refund agent with a three-layer isolation fix. Capped at 78 because it's a developer tutorial, not a product launch — impact stays within the engineering audience.