Course / Lesson 3 of 6
18 min · sanitized real case
Proof gates & total coverage
Objective: Design a proof gate that covers everything — because a partial gate is not a weaker defense, it is an invitation to bypass.
First, in plain language
A proof gate is a door that only opens when every unit of work presents a genuinely executed proof. If the door watches 99% of units, the remaining 1% is not "less protected" — it becomes the preferred route for any work that wants to pass without proof, by accident or by construction.
The real mission's discipline was adversarial: attack your own gate, repair the minimum, and attack again. It took seven rounds. The gate only closed when a battery of thirteen known attacks passed 13/13 — with a Validator that had no authorship over the attacked code.
Open the technical layer
The seven rounds (each one: attack → minimal repair → re-attack):
| Round | Bypass found | Minimal repair |
|---|---|---|
| 1 | Units without an id stamp were invisible to the gate. | Stamp every task; an untagged executable becomes its own unit, flagged for review. |
| 2 | Forgeable metadata: a spurious kind:'proof' hid work; an id collision gave a free ride on someone else's proof. | Exemption only by complete form (kind + id + numeric proof index); id collision fails closed. |
| 3 | A command hidden inside the tag of an already-proven unit. | Inside a tagged unit, every command requires complete proof form. |
| 4 | Coordination subtasks ran invisible commands in a child sub-run (flat coverage). | Every command leaf must be complete proof, otherwise error. |
| 5 | Misaligned jurisdiction: the gate only looked at the top level; a failing proof leaf converged. | The gate flattens subtasks; a failing or unjournaled leaf takes the gate down. |
| 6 | Ghost leaf: an internal kind with no command converged. | A phantom instrument leaf becomes an error. |
| 7 | "Greatest hits" battery: all previous attacks together. | 13/13; total command coverage; residuals documented, not hidden. |
Structural lesson: no repair "improved the code"; each one closed exactly the demonstrated bypass and was immediately re-attacked. The repository baseline stayed green throughout — the adversary here is the gate's logic, not the compiler.
Spot the bypass
Each card shows a configuration that would pass a naive gate. Choose where the bypass lives.