Notarize verifiable credentials on DLT for provability and order
The signature of a verifiable credential (VC) ensures integrity and immutability of the contained data by a digital signature. By default a VC also proclaims an issuance date which is singed along with the other data. The issue is that the issuer can sign an arbitrary date as the issuance date for the VC, what makes this particular data field gameable for the issuer. In order to make the issuance date verifiable, the VC has to be notarized upon creation. To do this we use distributed ledgers as a trusted third party, providing and immutable order and thereby timestamps to events.
Install the npm package
npm i vc-notarization
Notarize a VC in order to create a verifiable timestamp on the DLT
import { notarize, VerifiableCredential, NotarizationResponse } from 'vc-notarization';
const credential: VerifiableCredential = {
"@context": [
"https://www.w3.org/2018/credentials/v1",
"https://ssi.eecc.de/api/registry/context/productpassport",
"https://w3id.org/security/suites/ed25519-2020/v1"
],
"id": "https://ssi.eecc.de/api/registry/vc/cf43356c-a9f3-418a-a3ff-baca5a14d668",
"type": [
"VerifiableCredential",
"ProductPassportCredential"
],
"issuer": {
"id": "did:web:ssi.eecc.de",
"image": "https://id.eecc.de/assets/img/logo_big.png",
"name": "EECC"
},
"issuanceDate": "2023-01-25T16:01:26Z",
"credentialSubject": {
"id": "https://id.eecc.de/01/04012345999990/10/20210401-A/21/XYZ-1234",
"digital_link": "https://id.eecc.de/01/04012345999990/10/20210401-A/21/XYZ-1234"
},
"proof": {
"type": "Ed25519Signature2020",
"created": "2023-01-25T16:01:26Z",
"proofPurpose": "assertionMethod",
"verificationMethod": "did:web:ssi.eecc.de#z6MkoHWsmSZnHisAxnVdokYHnXaVqWFZ4H33FnNg13zyymxd",
"proofValue": "z5YUnCUVWgAwc1iTQ61jtUyjBNLZELGMxnbsekFDQLd4ZNbPo45we4xxZjV5pqb3jqPo7ryKMmMY9dySNERz1huLJ"
}
}
notarize(credential)
.then((res: NotarizationResponse) => {
console.log(`The credentials hash was published by transaction ${res.transactionId}`)
});Verify the issuance date of a VC using the notarized timestamp on the DLT if it exists
import { verifyTimestamp, VerifiableCredential } from 'vc-notarization';
const credential: VerifiableCredential = {
"@context": [
"https://www.w3.org/2018/credentials/v1",
"https://ssi.eecc.de/api/registry/context/productpassport",
"https://w3id.org/security/suites/ed25519-2020/v1"
],
"id": "https://ssi.eecc.de/api/registry/vc/cf43356c-a9f3-418a-a3ff-baca5a14d668",
"type": [
"VerifiableCredential",
"ProductPassportCredential"
],
"issuer": {
"id": "did:web:ssi.eecc.de",
"image": "https://id.eecc.de/assets/img/logo_big.png",
"name": "EECC"
},
"issuanceDate": "2023-01-25T16:01:26Z",
"credentialSubject": {
"id": "https://id.eecc.de/01/04012345999990/10/20210401-A/21/XYZ-1234",
"digital_link": "https://id.eecc.de/01/04012345999990/10/20210401-A/21/XYZ-1234"
},
"proof": {
"type": "Ed25519Signature2020",
"created": "2023-01-25T16:01:26Z",
"proofPurpose": "assertionMethod",
"verificationMethod": "did:web:ssi.eecc.de#z6MkoHWsmSZnHisAxnVdokYHnXaVqWFZ4H33FnNg13zyymxd",
"proofValue": "z5YUnCUVWgAwc1iTQ61jtUyjBNLZELGMxnbsekFDQLd4ZNbPo45we4xxZjV5pqb3jqPo7ryKMmMY9dySNERz1huLJ"
}
}
verifyTimestamp(credential)
.then((timestamp: Date) => {
console.log(timestamp)
});