Writing · Field notes
Field notes
Case studies and notes on AI security, drawn from the systems we build and run. No think-pieces — the work, and what it taught us.
Case study · Prompt injection
How we built a prompt-injection-hardened AI receptionist on Cloudflare's free tier
We dogfooded the attack we sell defense against: the threat model, the layered defenses, and an honest account of what we deliberately did not build.
Read → Jun 2026Security engineering · Eval harness
Building a reproducible adversarial evaluation harness for LLM injection defenses
How we built a portable, parameterized eval harness that runs production triage logic against 20 labeled cases and turns "hardened" into a number you can reproduce.
Read → Jun 2026Agent security · Methodology
Patterns and pitfalls in agentic AI security — reviewing systems that act
A practical framework for agentic AI security review: tool-abuse patterns, context poisoning in multi-turn sessions, and why authorization must live outside the model.
Read → Jun 2026Security engineering · Cryptographic provenance
The Seal VPE protocol — cryptographic provenance for AI agent prompts
Seal’s Verifiable Prompt Envelope (VPE) protocol replaces linguistic injection detection with cryptographic prompt signing. How it works, why it matters, and what we’ve learned building it.
Read →More in progress — published as work becomes ready.