...
npm install elliptic
npm install js-sha3
...
let elliptic = require('elliptic');
let sha3 = require('js-sha3');
let ec = new elliptic.ec('secp256k1');
// let keyPair = ec.genKeyPair(); // Generate random keys
let keyPair = ec.keyFromPrivate(
"97ddae0f3a25b92268175400149d65d6887b9cefaf28ea2c078e05cdc15a3c0a");
let privKey = keyPair.getPrivate("hex");
let pubKey = keyPair.getPublic();
console.log(`Private key: ${privKey}`);
console.log("Public key :", pubKey.encode("hex").substr(2));
console.log("Public key (compressed):",
pubKey.encodeCompressed("hex"));
let msg = 'Message for signing';
let msgHash = sha3.keccak256(msg);
let signature =
ec.sign(msgHash, privKey, "hex", {canonical: true});
console.log(`Msg: ${msg}`);
console.log(`Msg hash: ${msgHash}`);
console.log("Signature:", signature);
let hexToDecimal = (x) => ec.keyFromPrivate(x, "hex")
.getPrivate().toString(10);
let pubKeyRecovered = ec.recoverPubKey(
hexToDecimal(msgHash), signature,
signature.recoveryParam, "hex");
console.log("Recovered pubKey:",
pubKeyRecovered.encodeCompressed("hex"));
let validSig = ec.verify(
msgHash, signature, pubKeyRecovered);
console.log("Signature valid?", validSig);