Blockchain Vocabulary v1

Terminology

The following terms are used to describe concepts involved in the generation and verification of the Linked Data Proof signature suite.

Please review [[LD-PROOFS]] for more details regarding linked data proof suites.

canonical form: The output of applying a canonicalization algorithm to an input document.
canonicalization algorithm: An algorithm that takes an input document that has more than one possible representation and always transforms it into a canonical form. This process is sometimes also called normalization.
digest algorithm: An algorithm that takes a input message and produces a cryptographic output message that is often many orders of magnitude smaller than the input message. These algorithms are often 1) very fast, 2) non-reversible, 3) cause the output to change significantly when even one bit of the input message changes, and 4) make it infeasible to find two different inputs for the same output.
signature algorithm: An algorithm that takes an input message and produces an output value where the receiver of the message can mathematically verify that the message has not been modified in transit and came from someone possessing a particular secret.
signature suite: A specified set of cryptographic primitives typically consisting of a canonicalization algorithm, a message digest algorithm, and a signature algorithm that are bundled together by cryptographers for developers for the purposes of safety and convenience.

The Blockchain Vocabulary

The blockchain vocabulary is available via:

        {
          "@context": ["https://w3id.org/blockchain/v1"]
        }

The following classes are available for specifying information related to blockchain.

blockchainAccountId

A blockchain account id.

Term	blockchainAccountId
URL	https://w3id.org/security#blockchainAccountId
Expected Value	A blockchain account id.

privateKeyJwk

A JWK private key.

Term	privateKeyJwk
URL	https://w3id.org/security#privateKeyJwk
Expected Value	A JWK private key.

BlockchainVerificationMethod2021

A verificationMethod type for blockchains.

Term	BlockchainVerificationMethod2021
URL	https://w3id.org/security#BlockchainVerificationMethod2021
Expected Value	Class

BlockchainSignature2021

A linked data proof type for blockchain verification methods.

Term	BlockchainSignature2021
URL	https://w3id.org/security#BlockchainSignature2021
Expected Value	Class

Linked Data Suite Definition

The Blockchain vocabulary defined in this document may be used to construct linked data proofs.

Parameter	Value	Specification
canonicalization algorithm	https://w3id.org/security#URDNA2015	[[RDF-DATASET-NORMALIZATION]]
digest algorithm	SHA-256	[[SHA-3]]
signature algorithm	JSON Web Signature (JWS) Unencoded Payload Option	[[RFC7797]]

        {
          "id": "https:/w3id.org/security#BlockchainSignature2021",
          "type": "SignatureSuite",
          "canonicalizationAlgorithm": "https://w3id.org/security#URDNA2015",
          "digestAlgorithm": "https://tools.ietf.org/html/rfc5754#section-2.2",
          "signatureAlgorithm": "https://tools.ietf.org/html/rfc7797"
        }

Examples

This specification describes a Linked Data vocabulary for asserting Verifiable Credentials related to Blockchain.

DID Document

The Blockchain vocabulary can be used with decentralized identifiers.

{
    "@context": [
        "https://www.w3.org/ns/did/v1",
        "https://w3id.org/blockchain/v1"
    ],
    "id": "did:example:123",
    "assertionMethod": [
        {
        "id": "did:example:123#test-id",
        "type": "BlockchainVerificationMethod2021",
        "controller": "did:example:123",
        "blockchainAccountId": "0xF20cC6c5B9fef13Cb75300BbD059C176D18d3d01@eip155:1"
        }
    ]
}

Verifiable Credential

The blockchain vocabulary can be used with verifiable credentials.

{
    "@context": [
        "https://www.w3.org/2018/credentials/v1",
        "https://w3id.org/blockchain/v1"
    ],
    "id": "http://example.gov/credentials/3732",
    "type": ["VerifiableCredential"],
    "issuer": {
        "id": "did:example:123"
    },
    "issuanceDate": "2020-03-10T04:24:12.164Z",
    "credentialSubject": {
        "id": "did:example:456"
    },
    "proof": {
        "type": "BlockchainSignature2021",
        "created": "2019-12-11T03:50:55Z",
        "jws": "eyJhbGciOiJFUzI1NkstUiIsImI2NCI6ZmFsc2UsImNyaXQiOlsiYjY0Il19..6X2f25HwuRcSHXTIWgkkQILIUyfZqMaQcfTgfCyofyNvSGmkPCaTawFqCPFu8NZTdVUiP6OWuioCfFq0CVfpWAA",
        "proofPurpose": "assertionMethod",
        "verificationMethod": "did:example:123#test-id"
    }
}