Glossary · Tamga Network

Core concepts

Tamga Network: A Digital Trust Infrastructure that unites digital identity, verifiable credentials, authorization and immutable records under a single architecture. It is not a blockchain network: today trust is anchored in signed trust lists; a permissioned ledger may be added later.
Digital Trust Infrastructure: The layer that provides trust in the digital world as a shared infrastructure service. Instead of each application solving the trust problem separately, it provides a common trust layer.
Tamga Wallet: Tamga’s wallet app and the infrastructure’s first end-user product. It keeps a person’s credentials on their phone and shares only the fields they approve. Tamga Wallet is not Tamga Network itself.
Trust Mesh: Not a central authority, but a mesh of interoperable, independent trust networks. Each country keeps its own network while connecting through shared standards.

Tamga today

Trust list: A signed, versioned, hash-chained public register of institutions, their certificates, what they may issue and their status. The EU model (ETSI TS 119 612).
Anchor log: A public, append-only log where every revocation-list publication and schema change is written as a signed line, at least hourly.
SD-JWT VC: The IETF credential format Tamga uses by default: each field hidden behind a salted hash, revealed only with the holder’s approval.
mdoc (ISO 18013-5): The mobile-document format of the mobile driving licence. Tamga issues the identity credential also as an mdoc, e.g. for age checks.
OpenID4VCI / OpenID4VP: The OpenID standards for issuing credentials into a wallet and presenting them to a verifier — the EUDI profiles.
Wallet Unit Attestation (WUA): A short-lived statement from the wallet provider that the app is a genuine wallet; issuers require it.
Per-verifier copy: The wallet holds several copies of each credential, each bound to a different device key, and gives each verifier a different one — so verifiers cannot link the holder.
ACCEPTED / REJECTED / INDETERMINATE: The three verification outcomes. INDETERMINATE means “could not be checked right now” and is never shown as a rejection.
Passkey: A WebAuthn key on your device for one website. After signing up with the wallet, daily sign-in uses a passkey and shares no fields.

Identity and trust

Digital Identity: The verifiable representation of an entity on the network (individual, institution, object). The starting point of the ecosystem.
VC — Verifiable Credential: A verifiable document. A digital document with an embedded digital signature that can be verified without going to the source (diploma, licence, etc.).
SSI: Self-Sovereign Identity. The approach where control of identity belongs not to a central institution but to the user themselves.
Issuer – Holder – Verifier: The trust triangle. The Issuer issues and signs the credential; the Holder carries and presents it in their wallet; the Verifier checks the signature without going to the source.

Cryptography and records

Hash: A fixed-length, one-way digital fingerprint produced from data. Used to prove that the data has not changed.
Digital signature: Sealing the hash of data with a private key. Verified with the public key; proves the source and integrity of a document.
PKI: Public Key Infrastructure. A chain of trust that records which key belongs to which institution and what it is authorized to do.
SD-JWT: Selective Disclosure JWT. A format that lets only the necessary fields be revealed without breaking a document’s integrity.
ZKP: Zero-Knowledge Proof. A technique for proving something without revealing its value at all.
On-chain / Off-chain: On-chain: non-personal trust data kept on the blockchain. Off-chain: operational data and documents kept in the wallet/institution. Today Tamga has no chain; public trust data lives in signed trust lists.

Network and standards

Permissioned network: A blockchain network where the validators are specific and trusted. The ledger Tamga plans is one.
Consensus: The mechanism by which the network’s nodes agree on the content of the next block. Tamga uses QBFT (the Byzantine Fault Tolerance family).
Hyperledger Besu: The open-source, EVM-compatible client Tamga chose for its future ledger (once at least two independent operators join).
eIDAS 2.0: The EU’s electronic identity and trust services framework; it makes a digital identity wallet mandatory for every member state.
EUDI Wallet: European Digital Identity Wallet — the EU citizen’s digital identity wallet (the application layer).

Advanced architecture

Root Identity: The unique identity record issued by the state that holds the link to the real person. Only the issuer + a guardian threshold can access it.
Pseudonym: A separate, mutually unlinkable identity derived from the root identity for each application. Prevents cross-application profiling.
Unlinkability: The property that the same person’s identities in different applications cannot be mathematically correlated.
HD derivation (BIP32/SLIP-0010): Hierarchical deterministic key derivation. A method of producing unlimited, unlinkable child keys from a single seed along fixed paths.
BIP39 mnemonic: A 24-word recovery phrase; converted to a seed (PBKDF2-HMAC-SHA512). The source of all the user’s keys.
Escrow: A record holding the link between pseudonyms and the root identity, protected by threshold encryption. Opened only with authority.
Threshold encryption: A model where the decryption authority is split into shares and can only be used when enough (K-of-N) shares come together.
Distributed Key Generation (DKG): A protocol where guardians jointly generate a shared key so that no single party ever holds it; the key is never reconstructed — only a specific ciphertext is opened by a quorum (threshold ElGamal).
Guardian: One of an institutional set of five per state (judiciary, data-protection authority, civil-registry authority, ombudsman, a parliament-appointed member), each holding one threshold share. A 3-of-5 quorum with at least one non-executive approval is required to open.
Envelope encryption: Encrypting data with a DEK and wrapping the DEK with a KEK; since the server never sees the KEK, it cannot read the content.
DEK / KEK: Data Encryption Key / Key Encryption Key. The two-layer keys in envelope encryption that encrypt the data and wrap that key.
Token Status List: The IETF revocation list Tamga uses: two bits per credential copy (valid, revoked, suspended) at a random position, signed and published at a fixed interval.
Challenge-response (FIDO2/WebAuthn): Authentication where, without sending a password, a random value from the server is signed with the private key and verified with the public key.
Secure Enclave / StrongBox: The secure area on iOS and Android where keys/PINs are stored in hardware isolation.
ICAO 9303: The e-passport/e-ID NFC chip verification standard. Used together with face matching in second-tier recovery.