@digitalcredentials/ed25519-verification-key-2020

Ed25519VerificationKey2020 Key Pair Library for Linked Data (@digitalcredentials/ed25519-verification-key-2020)

Javascript library for generating and working with Ed25519VerificationKey2020 key pairs, for use with crypto-ld.

Table of Contents

• Background
• Security
• Install
• Usage
• Contribute
• Commercial Support
• License

Background

(Forked from digitalbazaar/ed25519-verification-key-2020 v3.1.0 to provide TypeScript compatibility.)

For use with:

• @digitalcredentials/ed25519-signature-2020 ^2.0.0 crypto suite (with jsonld-signatures ^2.0.0)
• @digitalcredentials/vc ^2.0.0

See also (related specs):

• Ed25519VerificationKey2020 spec.

Security

As with most security- and cryptography-related tools, the overall security of your system will largely depend on your design decisions.

Install

• Node.js 14+ is required.

To install locally (for development):

git clone https://github.com/digitalcredentials/ed25519-verification-key-2020.git
cd ed25519-verification-key-2020
npm install

Usage

Generating a new public/private key pair

To generate a new public/private key pair:

• {string} [controller] Optional controller URI or DID to initialize the generated key. (This will also init the key id.)
• {string} [seed] Optional deterministic seed value from which to generate the key.

import {Ed25519VerificationKey2020} from '@digitalcredentials/ed25519-verification-key-2020';

const edKeyPair = await Ed25519VerificationKey2020.generate();

Importing a key pair from storage

To create an instance of a public/private key pair from data imported from storage, use .from():

const serializedKeyPair = { ... };

const keyPair = await Ed25519VerificationKey2020.from(serializedKeyPair);

Exporting the public key only

To export just the public key of a pair:

await keyPair.export({publicKey: true});
// ->
{ 
  type: 'Ed25519VerificationKey2020',
  id: 'did:example:1234#z6MkszZtxCmA2Ce4vUV132PCuLQmwnaDD5mw2L23fGNnsiX3',
  controller: 'did:example:1234',
  publicKeyMultibase: 'zEYJrMxWigf9boyeJMTRN4Ern8DJMoCXaLK77pzQmxVjf'
}

Exporting the full public-private key pair

To export the full key pair, including private key (warning: this should be a carefully considered operation, best left to dedicated Key Management Systems):

await keyPair.export({publicKey: true, privateKey: true});
// ->
{
  type: 'Ed25519VerificationKey2020',
  id: 'did:example:1234#z6MkszZtxCmA2Ce4vUV132PCuLQmwnaDD5mw2L23fGNnsiX3',
  controller: 'did:example:1234',
  publicKeyMultibase: 'zEYJrMxWigf9boyeJMTRN4Ern8DJMoCXaLK77pzQmxVjf',
  privateKeyMultibase: 'z4E7Q4neNHwv3pXUNzUjzc6TTYspqn9Aw6vakpRKpbVrCzwKWD4hQDHnxuhfrTaMjnR8BTp9NeUvJiwJoSUM6xHAZ'
}

Generating and verifying key fingerprint

To generate a fingerprint:

keyPair.fingerprint();
// ->
'z6MkszZtxCmA2Ce4vUV132PCuLQmwnaDD5mw2L23fGNnsiX3'

To verify a fingerprint:

const fingerprint = 'z6MkszZtxCmA2Ce4vUV132PCuLQmwnaDD5mw2L23fGNnsiX3';
keyPair.verifyFingerprint({fingerprint});
// ->
{valid: true}

Creating a signer function

In order to perform a cryptographic signature, you need to create a sign function, and then invoke it.

const keyPair = Ed25519VerificationKey2020.generate();

const {sign} = keyPair.signer();

// data is a Uint8Array of bytes
const data = (new TextEncoder()).encode('test data goes here');
// Signing also outputs a Uint8Array, which you can serialize to text etc.
const signatureValueBytes = await sign({data});

Creating a verifier function

In order to verify a cryptographic signature, you need to create a verify function, and then invoke it (passing it the data to verify, and the signature).

const keyPair = Ed25519VerificationKey2020.generate();

const {verify} = keyPair.verifier();

const valid = await verify({data, signature});
// true

Contribute

PRs accepted.

If editing the Readme, please conform to the standard-readme specification.

License

• MIT License - DCC - TypeScript compatibility.
• New BSD License (3-clause) © 2020-2021 Digital Bazaar - Initial implementation.