# WI-1 lease broker security notes

- Trusted identity comes only from Linux `SO_PEERCRED` plus `/proc` starttime, never request identity fields.
- Descendant authorization is anchored to `(pid,starttime)` and uses a complete second starttime pass to fail closed on disappearance or PID-reuse races.
- Runtime generations are monotonic per anchor; a bump revokes prior-incarnation tokens before persistence commits.
- Session IDs and cycle tokens use the OS cryptographic RNG. `Math.random` and model output are not token sources.
- Framing and persistence failures fail closed. Sensitive tokens are not logged.
- Same-principal filesystem modes are minimum hardening, not socket authenticity against the same UID. Distinct-principal service isolation is required for that stronger claim.
- WI-2+ security surfaces—receipts, promotion transactions, mutator gates, hooks, payload construction, and recovery—are explicitly out of scope.

Coordinator security review must rerun the real socket/peercred acceptance suite on an unrestricted Linux runner and obtain the mandated independent Opus-SECREV review before integration.