TigerTag+ Certified

Purpose

Certified is the level that can prove where a chip came from. A TigerTag+ that additionally carries a cryptographic signature is a TigerTag+ Certified. The signature is written by a manufacturer holding TigerTag+ certification, who is given the signing tools as part of it; TigerTag holds the private key.

It is the only one of the three levels not open to everyone, and the only one that answers a question the other two cannot: is this spool genuine?

The three levels, side by side

	TigerTag	TigerTag+	TigerTag+ Certified
Print data, on the chip	✅	✅	✅
Works fully offline	✅	✅	✅
Catalogue product ID, on the chip	—	✅	✅
Enrichment metadata, via the Web API, optional	—	✅	✅
Origin signature, on the chip	—	—	✅
Who can produce one	everyone	everyone	a certified manufacturer

Read the left column carefully: the enrichment metadata is the one row that does not live on the chip. It is looked up from the catalogue when you happen to be online, and it can improve after the chip is written — which is precisely why it can never be something the chip needs. Everything the printer requires is in the rows marked on the chip, which is what keeps all three levels 100 % offline.

Verifying is free — issuing is what certification grants

Verifying a signature is free, offline and unrestricted: the public keys are published, and any reader can check one without an account or a network. Issuing one is what certification grants.

The signed message deliberately covers the chip’s own UID, so a signed payload copied onto another chip no longer matches it: a cloned tag fails verification, on the customer’s own phone. The same property is why the two chips of one spool carry two different signatures (how the two chips are bound).

Where it sits

flowchart LR
  CAT[("Official catalogue")] -- "product id + metadata" --> TTP["TigerTag+"]
  TTP -- "signed by a certified manufacturer" --> CERT["TigerTag+ Certified"]
  CERT -- "verify offline, public key" --> ANY["Any reader, any phone"]
  TTP -- "read offline" --> ANY

The byte-level layout — chip type ids, the 64-byte signature area at pages 0x18–0x27 — is specified in TigerTag-RFID-Guide.

Who is certified

The authoritative list of manufacturers allowed to put the mark on a product is the certified partners registry. A logo on a chip, a carrier, a spool or its packaging is only authorized for the makers on that page.