Field notes

Concepts · 2026-06

The two-person rule for AI agents

Some actions are too consequential for one signature. M-of-N or ordered human approval, each signer bound to the exact action — the two-person rule made cryptographic, offline-verifiable, and fail-closed.

Financial · 2026-04

AI voice cloning fraud — defense by action binding

Voice authentication broke. The fix isn't a better voice model — it's moving the trust check off the voice channel entirely. Field guide for treasury, wire desks, and fraud ops.

Formal Methods · 2026-04

How formal verification works for protocols

TLA+ proves temporal properties across runs. Alloy bounds-checks structural invariants. A primer with worked examples from the EP spec.

MCP · 2026-04

MCP authorization best practices in 2026

Scope-level OAuth gets you to the door. For tools that move money, change infrastructure, or trigger irreversible state, you need the next layer.

Concepts · 2026-04

What is pre-action authorization?

Sessions and scopes authorize the actor. Pre-action authorization authorizes the action — the destination, the amount, the exact parameters, before execution.