Platform: AMD SEV-SNP¶

A signed SEV-SNP report supplies evidence about a confidential VM. To use it for TRACE, a verifier must check the report's authenticity, accepted platform state and measurement, freshness, and binding to the record-signing key. A digest copied into JSON is not that verification.

Measurement and key binding¶

The SNP report's MEASUREMENT field is a 48-byte launch measurement. It is distinct from guest-supplied REPORT_DATA, which a profile can use to bind a key and challenge. See Google's SEV-SNP ABI implementation for the field sizes.

An expected launch measurement must be independently approved. A certificate-distribution endpoint supplies signing collateral; it is not a Reference Integrity Manifest describing the expected workload. Matching a report's measurement to a record also does not establish what that measurement represents without the producing profile and reference values.

TRACE representation¶

Standalone records use runtime.platform="amd-sev-snp", or azure-cvm-sev-snp when the producing profile requires that identifier. runtime.measurement uses the schema's digest syntax; the producer must define its relationship to the verified report. Do not hash an already-computed measurement again unless the profile explicitly defines that transformation.

Hardware appraisal supports Level 1. Level 2 adds a separately verified transparency anchor. See trust levels.

Deployment and verification¶

Cloud support depends on machine family, region, firmware, and guest configuration. For GCP, consult the current Confidential VM configurations. C3 is an Intel TDX family; N2D is used for AMD SEV-SNP.

For the actual AgenTrust implementation and recorded hardware runs, use cMCP hardware validation and its verification tutorial. The TRACE SDK's signature verifier does not perform this hardware appraisal.