How to encrypt and decrypt a message with TweetNaCl.js

tweetnacl-test.js

const tweetnacl = require('tweetnacl'); // https://github.com/dchest/tweetnacl-js
tweetnacl.util = require('tweetnacl-util'); // https://github.com/dchest/tweetnacl-util-js

// utility function to display the Uint8Array
const asciiArmored = arr => tweetnacl.util.encodeBase64(arr);

// generate the key to encrypt a message
const secretKey = tweetnacl.randomBytes(32);
console.log(`secret key: ${asciiArmored(secretKey)}`);

// the nonce
const nonce = tweetnacl.randomBytes(24);
console.log(`nonce: ${asciiArmored(nonce)}`);

// the message to be encrypted
const message = 'some secret message with some secret credentials';
const decodedMessage = tweetnacl.util.decodeUTF8(message);

// perform the encryption
const encryptedMessage = tweetnacl.secretbox(decodedMessage, nonce, secretKey);
console.log(`encrypted message: ${asciiArmored(encryptedMessage)}`);

// decrypt the encrypted message
const originalMessage = tweetnacl.secretbox.open(
  encryptedMessage,
  nonce,
  secretKey
);

console.log(`decrypted message: ${tweetnacl.util.encodeUTF8(originalMessage)}`);

It is really important to use a unique nonce for each encryption. and decryption all catigory