What is a digital identity card?

A digital identity card is an identity credential — photograph, name, date of birth, an identifier — presented from a phone rather than from a piece of plastic. The phrase is used for three quite different things, and the differences matter more than the shared name suggests.

• An image of a card. A photo of your licence or passport stored in your phone. It is digital only in the sense that a file is digital; it carries none of a card's physical protections and none of a credential's cryptographic ones.
• A government-issued digital licence. Some state and territory governments display a driver licence inside their service apps, with presentation rules set by the issuer — checkable at a counter, with the issuer able to stand behind it.
• A verifiable credential. A signed statement held in a credential wallet, presented as a proof a service can verify cryptographically. This is the strongest of the three, because trust flows from a signature rather than from an image's appearance.

Australia does not issue a national identity card — that has been the country's consistent position across decades of debate. Digital identity in Australia instead arrives as services: the Australian Government's Digital ID System and its sign-in app for participating government services, state and territory digital driver licences, and independent wallets like this one.

There is no single card — physical or digital — that proves identity everywhere. Instead, identity is established through a combination of documents, service credentials and verification results, which is precisely the environment in which a digital identity service operates.

A card is a fixed bundle: presenting it for one fact presents everything on it. Ask whether you are over 18 and the card also answers your name, your exact birth date, your address and your number. That over-answering is the privacy problem with cards — physical and digital alike — and it is the problem zero-knowledge proofs were built to solve.

A credential wallet inverts the bundle. Each question gets its own narrow answer — a threshold proof, a single verified claim, a tier — approved per request and recorded in your consent history. What each credential reveals and withholds is catalogued at credentials and proofs.

Practically everyone has, at some point, photographed a licence or passport to send to someone who asked. It is worth unlearning. Every such copy is identity data in a stranger's storage system, and copies leak at exactly the moment you forget they exist. Where a photo is genuinely required, treat it as a one-off; where only a fact is required — an age, a name, an address — offer the fact instead.

The everyday version of this habit — locks, passkeys, breach alerts and refusing needless document circulation — is collected in how to protect your identity for free.