Lesson 9.1 · 11 min read
Monitoring attestation in production
Signals to collect, what normal looks like, and which events should page someone.
What to log
Every attestation decision is a security event. Log it from the verifier or key service, outside the TEE, so a compromised workload cannot suppress it.
| Signal | Why it matters | Alert when |
|---|---|---|
| Attestation failures by reason | Shows attacks, misconfiguration or stale reference values | A burst of failures, or any failure due to debug mode or unknown measurement |
| Measurements seen in production | Confirms only approved builds are running | A measurement not in the approved list appears |
| TCB levels reported | Shows platforms that are behind on firmware | A platform reports a TCB below your minimum |
| Key release events | The core control in the design | Release to an unexpected identity, region or at an unusual rate |
| Policy changes | Changing a policy changes who gets keys | Any change outside an approved change ticket |
Key takeaways
- Log attestation decisions from outside the TEE.
- Alert on unknown measurements, debug evidence, low TCB and unexpected key releases.
- Enable and retain cloud audit logs for key services in advance.