Blog ← What is a DID? A plain-language explainer
What is a DID? A plain-language explainer
2026-08-28
Every online "identity" you have today is issued by someone else: your phone number by a carrier, your social account by a platform, your email by a provider. If the platform closes your account, that "you" disappears. A DID — decentralized identifier, a globally unique identity number anyone can look up — solves exactly this: an identity that the whole world can recognize and verify without depending on any single company. It is an open standard published by the W3C, the body behind the core standards of the web.
Why must the number be globally unique?
An AI agent works on platform A today and talks to company B's systems tomorrow. If every platform issues its own numbers, one agent becomes ten mutually unrecognizable strangers across ten systems, and its reputation never travels with it. Only a globally unique identifier makes "it is the same one" hold across systems — like a phone number that still connects from abroad with a country code.
Why not one company's database?
The traditional answer is a central database: whoever wants to check an identity asks me. Three problems: the company can fold, it can ban you, and the database can be breached. A DID flips the model — the identifier is bound to a public key that anyone can use to check signatures, while the holder keeps the matching private key. Verifying an identity becomes a math exercise, not a matter of "some company's server is online and has the final say."
did:web — landing DIDs on domain names
Among the many DID methods, the easiest to grasp is did:web, which borrows the existing domain-name system. did:web:jiaozi.io translates, by rule, to "fetch the identity dossier at https://jiaozi.io/.well-known/did.json". That dossier — the DID document — lists the identity's public keys, and you can open it in a browser. Domains are already globally unique and universally reachable, so did:web stands on the shoulders of existing infrastructure.
How does this relate to JIAOZI credentials?
A DID is just "a number plus keys" — necessary but not sufficient, like a phone number without any document saying whose it is and whom it may act for. What JIAOZI does is issue each AI agent a verifiable identity credential based on the W3C DID/VC standards: the agent's DID, its owner, its authorized scope and its live status. Anyone can verify the credential for free — no signup, and not even through us.
This article is a technical explainer, not legal advice. This service provides technical identity verification and does not constitute electronic certification under the PRC Electronic Signature Law.