Interpreting Hardware Attestation¶
A platform name and measurement in a signed TRACE record are claims. To treat them as hardware evidence, a recipient needs authenticated attestation evidence, accepted reference values, and a binding to the signing key. This guide explains that distinction; it does not provision a TEE.
Start with the right format¶
Standalone TRACE records use the canonical schema. cMCP emits a distinct RuntimeClaim envelope and uses its own verifier. Do not pass that envelope directly to agentrust_trace.verify_record.
| Evidence | What the recipient checks |
|---|---|
| Signed record | Schema, supported profile, trusted signing key, signature, freshness, configured revocation and nonce checks |
| Hardware report or quote | Signature chain and collateral, platform policy, expected measurement, fresh challenge |
| Key binding | The authenticated report binds this record-signing key under the producing profile |
| Policy and transcript | Independently obtained artifacts match the signed commitments; their meaning depends on the producer |
| Transparency | Inclusion proof and an independently trusted log/checkpoint; a URL alone is insufficient |
Software-only records¶
runtime.platform="software-only" carries no hardware assurance. Its measurement can be a producer-defined software commitment; all-zero is appropriate only when no commitment is offered. Software-signed records can support uses whose trust policy accepts software key custody. They must not satisfy a requirement for verified hardware evidence.
Hardware-specific evidence¶
- AMD SEV-SNP: distinguish the launch measurement from guest-supplied report data.
- Intel TDX: interpret MRTD and RTMRs under the producing profile.
- NVIDIA H100: GPU appraisal does not automatically establish CPU workload or signing-key identity.
- TPM2: a quote and trusted attestation key can establish measured-state evidence. A TPM is not a general-purpose enclave for the application; it does not by itself protect agent process memory from the host OS. See cMCP's TPM security model.
What the TRACE SDK does¶
verify_record verifies the standalone signed object. It does not collect or appraise hardware quotes, fetch a Reference Integrity Manifest, or independently substantiate appraisal.status. There is no verify-hardware command in this package.
For cMCP evidence, use its verification tutorial, approved policy/catalog hashes, and required attestation inputs. For a local software example, use quick start.
Report the checks performed¶
Hardware appraisal corresponds to Level 1; Level 2 adds transparency anchoring. Report unavailable evidence as unavailable, and a contradictory result as a failure. A record that says affirming does not authorize an action without the recipient's own acceptance policy. See trust levels and verification outcomes.