JSON-LD 1.1 is being formally specified in the W3C JSON-LD Working Group. To participate in this work, please join the W3C and then join the Working Group.
Per ld-signatures, this Signature Suite defines the following:
{
"id": "https://identity.foundation/EcdsaSecp256k1RecoverySignature2020#EcdsaSecp256k1RecoverySignature2020",
"type": "SignatureSuite",
"canonicalizationAlgorithm": "https://w3id.org/security#URDNA2015",
"digestAlgorithm": "https://www.ietf.org/assignments/jwa-parameters#SHA256",
"signatureAlgorithm": "https://tools.ietf.org/html/rfc4880#section-11.4"
}
A jwk secp256k1 public key.
{
"id": "did:example:123#vm-1",
"controller": "did:example:123",
"type": "EcdsaSecp256k1RecoveryMethod2020",
"publicKeyJwk": {
"crv": "secp256k1",
"kid": "JUvpllMEYUZ2joO59UNui_XYDqxVqiFLLAJ8klWuPBw",
"kty": "EC",
"x": "dWCvM4fTdeM0KmloF57zxtBPXTOythHPMm1HCLrdd3A",
"y": "36uMVGM7hnw-N6GnjFcihWE3SkrhMLzzLCdPMXPEXlA"
}
}
A jwk secp256k1 private key.
{
"id": "did:example:123#vm-1",
"controller": "did:example:123",
"type": "EcdsaSecp256k1RecoveryMethod2020",
"privateKeyJwk": {
"crv": "secp256k1",
"d": "rhYFsBPF9q3-uZThy7B3c4LDF_8wnozFUAEm5LLC4Zw",
"kid": "JUvpllMEYUZ2joO59UNui_XYDqxVqiFLLAJ8klWuPBw",
"kty": "EC",
"x": "dWCvM4fTdeM0KmloF57zxtBPXTOythHPMm1HCLrdd3A",
"y": "36uMVGM7hnw-N6GnjFcihWE3SkrhMLzzLCdPMXPEXlA"
}
}
A hex encoded secp256k1 compressed public key.
{
"id": "did:example:123#key-0",
"type": "EcdsaSecp256k1RecoverySignature2020",
"publicKeyHex": "027560af3387d375e3342a6968179ef3c6d04f5d33b2b611cf326d4708badd7770"
}
A hex encoded secp256k1 compressed private key.
{
"id": "did:example:123#key-0",
"type": "EcdsaSecp256k1RecoverySignature2020",
"publicKeyHex": "278a5de700e29faae8e40e366ec5012b5ec63d36ec77e8a2417154cc1d25383f"
}
A hex encoded ethereumAddress address.
{
"id": "did:example:123#key-0",
"type": "EcdsaSecp256k1RecoverySignature2020",
"ethereumAddress": "0x89a932207c485f85226d86f7cd486a89a24fcc12"
}
A blockchain account ID according to CAIP-10.
{
"id": "did:example:123#key-0",
"type": "EcdsaSecp256k1RecoverySignature2020",
"blockchainAccountId": "eip155:1:0x89a932207c485f85226d86f7cd486a89a24fcc12"
}
This suite uses detached JWS using alg “ES256K-R” an unregistered, experimental ECDSA over secp256k1 with encoded recovery bit. Please review the details below.
ES256K-R is just ES256K with the recovery bit appended… making the signature 65 bytes instead of 64.
The recovery bit is used to extract the public key from the signature. See here.
^ please recommend a better source for describing ecdsa secp256k1 recoverable signature format.
The detached JWS must have the following header:
{
"alg": "ES256K-R",
"b64": false,
"crit": ["b64"]
}
This is what a proof with EcdsaSecp256k1RecoverySignature2020
looks like:
{
"type": "EcdsaSecp256k1RecoverySignature2020",
"created": "2020-04-11T21:07:06Z",
"verificationMethod": "did:example:123#vm-3",
"proofPurpose": "assertionMethod",
"jws": "eyJhbGciOiJFUzI1NkstUiIsImI2NCI6ZmFsc2UsImNyaXQiOlsiYjY0Il19..pp9eiLCMfN4EfSB3cbl3UxJ4TtgUaTfByDaaB6IZbXsnvIy5AUIFjbgaiFNtq9-3f8mP7foD_HXpjrdWZfzlwAE"
}