> For the complete documentation index, see [llms.txt](https://docs.zion.fyi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zion.fyi/architecture/did/did-universal-resource-identifier.md).

# DID Universal Resource Identifier

All DID Methods on sidetree share the same identifier format. The unique identifier segment is known as a [DID Suffix](https://identity.foundation/sidetree/spec/#did-suffix). This is derived from the initial state of the DID’s state data. Additionally, the [DID Suffix](https://identity.foundation/sidetree/spec/#did-suffix) is cryptographically bound to the initial PKI state of the DID, making sidetree DIDs self certifying. This enables a person who creates a DID knows their unique identifier at the moment of DID generation, and is secured cryptographically for instant use.\
\
The URI resolves to a [DID document](/architecture/did.md#did-document) based on the implementation of the specific DID method. This infrastructure could be a web server (similar threat model to current URL API calls), peer-to-peer discovery, anchor to the Bitcoin blockchain, IPFS or custom implementation devised by the controller. In our case we use DID:ION our implementation. 

## Short Form URI

Upon DID creation a short form DID URI is generated.

Short-Form DID URI Format:

```json
did:METHOD:<did-suffix>
```

Short-Form DID URI Example:

```json
did:ion:EiDahaOGH-liLLdDtTxEAdc8i-cfCz-WUcQdRJheMVNn3A
```

## Long Form URI

After DID generation there is an indeterminate period of time before DID operation is anchored, propagated, and processed by anchoring systems. To account for this, Sidetree generates a long-form DID URI that is an equivalent to Sidetree-based DIDs that is both self-certifying and self resolving. This allows DIDs to be immediately resolvable by including the DIDs initial state data within long-form DID URI. Long form DID URI are the same as short for DID URI with an additional colon-separated segment appended at the end. This segment is a JSON data payload that contains information required for DID operation.This JSON data is encoded and added after the [DID Suffix](https://identity.foundation/sidetree/spec/#did-suffix).

Long-Form URI JSON Payload data

```json
{
  "delta": {
    "patches": [
      {
        "action": "replace",
        "document": {
          "publicKeys": [
            {
              "id": "anySigningKeyId",
              "publicKeyJwk": {
                "crv": "secp256k1",
                "kty": "EC",
                "x": "H61vqAm_-TC3OrFSqPrEfSfg422NR8QHPqr0mLx64DM",
                "y": "s0WnWY87JriBjbyoY3FdUmifK7JJRLR65GtPthXeyuc"
              },
              "purposes": [
                "auth"
              ],
              "type": "EcdsaSecp256k1VerificationKey2019"
            }
          ],
          "services": [
            {
              "id": "anyServiceEndpointId",
              "type": "anyType",
              "serviceEndpoint": "http://any.endpoint"
            }
          ]
        }
      }
    ],
    "updateCommitment": "EiBMWE2JFaFipPdthcFiQek-SXTMi5IWIFXAN8hKFCyLJw"
  },
  "suffixData": {
    "deltaHash": "EiBP6gAOxx3YOL8PZPZG3medFgdqWSDayVX3u1W2f-IPEQ",
    "recoveryCommitment": "EiBg8oqvU0Zq_H5BoqmWf0IrhetQ91wXc5fDPpIjB9wW5w"
  }
}
```

Format of Long-Form DID URI:

```json
did:METHOD:<did-suffix>:<long-form-suffix-data>
```

Example of Long-Form DID URI:

{% code overflow="wrap" %}

```json
did:ion:EiAnKD8-jfdd0MDcZUjAbRgaThBrMxPTFOxcnfJhI7Ukaw: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#sig_72bd16
```

{% endcode %}

Long-Form DID URIs support the follow features:

* Resolving DID Documents of unpublished DIDs
* Authentication of unpublished DIDs
* Verification of credentials signed against unpublished DIDs