Sign (using private key) and Verify (using public key) in node.js #cryptography

digital-signature.js

import {createPrivateKey, generateKeyPairSync, sign, verify} from 'node:crypto'

const passphrase = 'passphrase'
const {publicKey, privateKey} = generateKeyPairSync('ed25519', {
  privateKeyEncoding: {format: 'pem', type: 'pkcs8', cipher: 'aes-256-cbc', passphrase},
  publicKeyEncoding: {format: 'pem', type: 'spki'},
})
console.log(privateKey, publicKey)

const message = 'Hello world!'
console.log({message})

const signature = sign(null, Buffer.from(message), createPrivateKey({key: privateKey, passphrase}))
console.log('signature:', signature.toString('hex'))

const verified = verify(null, Buffer.from(message), publicKey, signature)
console.log({verified})