HPO DID Method Specification

Hippocrat is a self-sovereign data protocol using bitcoin and peer-to-peer technology.

1. HPO DID Method Specific Identifier

HPO DID Method Specific Identifier format is following below:

hpo-did = "did:hpo:" + hpo-did-specific-idstring
hpo-did-specific-idstring = the first public key hex of HPO DID, same format as bitcoin public key

HPO DID Example:

did:hpo:030807a2c73c62760df3431f7cdeecf0fe898a7da61a7c598c17e372f93cb402e6

2. DID Document

2.1. HPO DID Document Example

HPO DID Document Example:

{
    "@context": "https://www.w3.org/ns/did/v1",
    "id": "did:hpo:030807a2c73c62760df3431f7cdeecf0fe898a7da61a7c598c17e372f93cb402e6",
    "verificationMethod": [
        {
            "id": "did:hpo:030807a2c73c62760df3431f7cdeecf0fe898a7da61a7c598c17e372f93cb402e6",
            "type": "EcdsaSecp256k1VerificationKey2019",
            "controller": "did:hpo:030807a2c73c62760df3431f7cdeecf0fe898a7da61a7c598c17e372f93cb402e6",
            "publicKeyHex": "030807a2c73c62760df3431f7cdeecf0fe898a7da61a7c598c17e372f93cb402e6"
        }
    ]
}

2.2. CRUD

Create

• Creation of HPO DID document is supported in hippocrat-wallet-sdk.
• HPO DID(or the data that can derive HPO DID) should be stored in user local storage.

Read

• User will fully owns DID in his or her own storage to achieve self-sovereignty.
• Basically, HPO DID is readable only when user allows on a client side.
• Additionally, the issuer can use peer-to-peer storage to provide the status of HPO DID.

Update

• Update is not supported for HPO DID document.

Delete (Revoke)

• Revoke by self can be simply done if user deletes in local.
• If the issuer stores the status of user's DID in public space(e.g. peer-to-peer storage), user can request to delete from that space.
• Resolver will use either user's local storage or peer-to-peer storage to search.

3. Security Considerations

• DID Document and Identifier are created following bitcoin spec(bip32, bip44 and so on) using hippocrat-wallet-sdk.
• Security level is same with bitcoin.

4. Privacy Considerations

• Privacy data can be stored in peer-to-peer storage and must be encrypted by user's public key using hippocrat-wallet-sdk.
• DID document itself does not include any privacy information.

References

[1]. https://github.com/bitcoin/bips

[2]. https://w3c.github.io/did-core