eth-ecies

ECIES encrypt/decrypt library for Ethereum

Installing

$ npm install eth-ecies

Usage

Encrypt

const ecies = require("eth-ecies");

const publicKey = 'e0d262b939cd0267cfbe3f004e2863d41d1f631ce33701a8920ba73925189f5d15be92cea3c58987aa47ca70216182ba6bd89026fc15edfe2092a66f59a14003';
const privateKey = '55bb4cb6407303de8e4c5a635021d3db12cb537305eeb6401612ce14b35d6690';
const data = '{foo:"bar",baz:42}';

function encrypt(publicKey, data) {
    let userPublicKey = new Buffer(publicKey, 'hex');
    let bufferData = new Buffer(data);

    let encryptedData = ecies.encrypt(userPublicKey, bufferData);

    return encryptedData.toString('base64')
}
// Note: Encrypted message is a 113+ byte buffer

Decrypt

const ecies = require("eth-ecies");

function decrypt(privateKey, encryptedData) {
    let userPrivateKey = new Buffer(privateKey, 'hex');
    let bufferEncryptedData = new Buffer(encryptedData, 'base64');

    let decryptedData = ecies.decrypt(userPrivateKey, bufferEncryptedData);
    
    return decryptedData.toString('utf8');
}

Notes

• To derive the public key from a private key, you can use ethereumjs-util module