How Tamga works
Trust lists: who may issue what
A signature proves who signed a document. It does not prove that the signer is a real university. That second question is answered by a trust list — a signed public register of institutions, their certificates, what they may issue and their current status.
What is in a trust list
- Root certificate authorities of each state, with their status.
- Issuers — universities, public bodies, ticket sellers — with their certificate fingerprint, category and assurance class, and the document types they are authorized for, each with a time window.
- Relying parties (verifiers) with the fields they may request. Your wallet compares every request with this scope and warns if a verifier asks for more.
- Wallet providers whose attestation keys vouch for genuine wallet apps.
- The document-type catalogue: each type’s metadata address and content hash.
There is no personal data in a trust list — only institutions, certificates, statuses, dates and addresses.
Why you can trust the list itself
- Signed. Every list is a signed JWS; verifiers use only the signed file and check the signer against a fixed root fingerprint published out of band.
- Versioned and hash-chained. Each version carries the hash of the previous one. Nothing is deleted; status changes are appended to a history.
- Always fresh. Every list carries a “next update” date; a stale list is not trusted.
- Anchor log. Every status-list publication and schema change is written as a signed line to a public, append-only log, at least hourly. A verifier can detect a list that was rolled back or rewritten.
https://trust.tamga.network/ lotl.jws list of lists: national lists, schemas, wallet providers tl-tr.jws Türkiye: root CAs, issuers, relying parties tl-az.jws · tl-kz.jws … reserved slots for the other member states anchors.jsonl anchor log: one signed line per event, at least hourly keys/root-fingerprints.json the root of trust (also at tamga.network/trust-anchor) archive/ every past version, never deleted
How a verifier uses it
Credential
signed by an institution
Trust list
authorized on the issue date?
Status list
revoked or suspended?
Result
accepted · rejected · indeterminate
Authorization is checked against the date the credential was issued. A diploma issued while the university was active stays valid even if the university is later suspended; new issuance stops at once. If the list cannot be reached or is out of date, the answer is indeterminate — never a false “rejected”.
Built for many states from day one
From lists to a ledger
Trust lists are what the EU itself uses (ETSI TS 119 612, the EUDI trusted lists). Every field maps to a smart-contract record, so the same data can later move to a permissioned ledger — once at least two independent operators join. The list history is then replayed and both are tested to give the same answer.