Trust Tiers

v0.3 renames the v0.2 compliance levels to trust tiers: how much a reader may rely on a passport, and how that reliance was verified. The governing rule is simple — a claimed tier never exceeds what the signatures prove.

Tier	Requires	Verified how
`self_declared`	Core fields present; self/platform signature or none	Schema validation
`attested`	A valid owner-key signature	Signature verification
`verified`	A valid signature with `role: verifier` whose key is on the accredited list, and who is not the dataset’s own owner	Verifier signature vs the accredited list
`full`	`verified` plus an L3 impact statement where the profile requires it	As above + L3
`posthoc`	L1/L4 reconstructed, `post_hoc: true`	Schema validation

Mapping from v0.2: ORP-Basic → self_declared, ORP-Standard → attested, ORP-Full → verified/full, ORP-PostHoc → posthoc. Your existing compliance_level field still validates; v0.3 additionally reports a trust_tier.

How a tier is earned

No key resolver supplied → a document with an attestation caps at self_declared (signatures present but unverified).
A valid owner signature → attested.
A valid verifier-role signature on the accredited list, where the verifier is not also the owner → verified (and full when an L3 impact statement is present).

⚠️

A verifier cannot verify its own datasets. The verified tier is granted only when the verifier key is distinct from the owner’s signing key, and the verifier’s kid appears on the accredited-verifier list (orp_validator/schemas/accredited_verifiers.json, empty by default — until a verifier is accredited, nothing reaches verified, which fails safe).

In Python

from orp_validator import validate
 
result = validate(
    "segment.yaml",
    profile="ORP-Ads",
    resolve_key=my_resolver,
    accredited_verifiers={"did:web:auditor.example#k1"},  # overrides the bundled list
)
print(result.trust_tier.value)  # e.g. "verified"

Rails and marketplaces may refuse purposes below a given tier; the protocol does not price tiers.

Next steps

Attestation — the signatures a tier is built on
Conformance — prove an implementation agrees

Profiles Usage Policy