Agent security engineering series
Threat-model, contain, authorize, and red-team tool-using agents with deterministic controls around the model.
Threat-Model an AI Agent: Sources, Sinks, Authority, and Blast Radius
A practical AI agent threat-modeling method that maps untrusted sources to dangerous sinks, then constrains identity, authority, data, and blast radius at deterministic runtime boundaries.
Prompt Injection Is a Boundary Problem, Not a Prompt Problem
Why "smarter prompts" don't defend against indirect prompt injection, and what changes when authority lives outside the model's view.
Agent Identity Is the New Trust Boundary
A practical model for separating agent identity, workload proof, user delegation, scoped authority, and audit across MCP and A2A.
Secure the MCP and Tool Supply Chain: Trust Must Be Continuous
How to secure MCP servers, remote tools, connectors, skills, and their outputs with admission controls, audience-bound authorization, least privilege, runtime containment, and revocation.
Build the Tool Gateway: The Boundary That Actually Stops a Bad Action
A build-along for the Tool Gateway: adapter manifests, typed envelopes, resolver checks, dispatch, and destructive-action boundaries.
Approval Gates in Code: The Destructive-Mode Handshake
A build-along for approval gates: frozen evidence, human signatures, gateway redemption, and replayable destructive-action handshakes.
Red-Team Agent Hijacking: Build a Security Eval Gate for Repeat Attacks
A practical agent-hijacking evaluation harness: scenario design, adaptive and repeated attempts, path-aware metrics, deterministic release gates, and production replay.