How Verification Works

How Verification Works

🇬🇧 English · 🇷🇺 Русский

No cryptography degree needed — here's the whole model.

The fingerprint idea

When a passport is minted, the system computes a SHA-256 hash — a unique fingerprint — of the passport document (and of each photo and file). Only these fingerprints go on the blockchain. Change one comma in the description, and the fingerprint no longer matches: tampering is instantly visible.

The blockchain acts as a public, permanent notary log: "this fingerprint was registered by this wallet at this time." Nobody — not even the project author — can edit or delete it.

The trust layers (strongest first)

Layer	What it proves	How
1. On-chain record	The passport exists, since when, issued by which wallet	Blockchain lookup — free, works forever
2. Data hash	The description you're reading is byte-for-byte the registered one	Compare fingerprint of .odpass content with on-chain dataHash
2a. Card & anchors (v0.6)	The readable on-chain card (title, author, short description) matches the file byte-for-byte; the identification anchors match on-chain anchorsHash	Automatic on v0.6 registries — any mismatch is reported as TAMPERED, not a warning
3. File / image hashes	The digital original or photos are the registered ones	Same fingerprint comparison per file
4. Issuer identity	A real person/organization stands behind the profile ID	Human step: find the ID on their official site
5. Institutional proofs	Experts or museums vouched for the object	On-chain proof records from P/M profiles (check their IDs the same way)
6. Physical seal (optional since v0.6)	The physical object is linked to the passport	Numbered seal (visual) or NFC chip (see NFC Seals)

No single layer is magic. A counterfeiter can copy a QR code — but can't fake the hashes, the timestamp, or the issuer's public identity, and physical distinguishing features are checked by human eyes.

Protection level, at a glance

The verifier sums the layers up into a single protection level so you don't have to read the whole table:

• 🛡 Base — a valid passport: the identification minimum is present and the hashes (and the on-chain card) match.
• 🛡🛡 Sealed — Base, plus a physical seal anchor (a numbered tamper-evident seal or an NFC chip).
• 🛡🛡🛡 Attested — Base, plus at least one institution (a P or M profile) has vouched for the object on-chain.

It's recomputed from the chain on every check — never stored in the passport, encoded in its ID, or printed on the object — so it can't go stale or be faked. A tampered, revoked, or flagged passport shows no level; the warning takes over. And the level measures the strength of the evidence, not a verdict of authenticity — the human checks stay decisive.

What the results mean

• AUTHENTIC — record found, hosted passport data matches the on-chain fingerprint.
• UNVERIFIABLE — record exists, but the passport bundle isn't reachable (issuer may host it later, or hands it over privately). The on-chain proof still stands.
• TAMPERED — the hosted data does not match the fingerprint. Red flag.
• INVALID — no such Passport ID on this registry.
• Seal results (SEAL_NFC_*) are separate — a seal check is about the physical object, not the document. See NFC Seals for what each level actually proves.

What ODP does NOT prove

Honesty matters more than marketing:

• It does not prove the legal authorship or ownership of a work — courts and experts do that.
• It does not prove a P- or M-profile is really a museum — you confirm that on the institution's official site.
• A passport for a fake object is still a fake object with a passport. The registry proves registration, humans prove authenticity — ODP gives them tamper-proof material to work with.