Javascript class logic on how to use localStorage to store and get data of any type and encrypt it

JavaScript class that provides methods for storing and retrieving encrypted data of any type using the localStorage API:

class SecureLocalStorage {
  constructor(secretKey) {
    this.secretKey = secretKey;

  encrypt(data) {
    const encryptedData = CryptoJS.AES.encrypt(JSON.stringify(data), this.secretKey).toString();
    return encryptedData;

  decrypt(encryptedData) {
    const decryptedBytes = CryptoJS.AES.decrypt(encryptedData, this.secretKey);
    const decryptedData = JSON.parse(decryptedBytes.toString(CryptoJS.enc.Utf8));
    return decryptedData;

  store(key, data) {
    const encryptedData = this.encrypt(data);
    localStorage.setItem(key, encryptedData);

  retrieve(key) {
    const encryptedData = localStorage.getItem(key);
    if (encryptedData) {
      const decryptedData = this.decrypt(encryptedData);
      return decryptedData;
    return null;

  remove(key) {

In this example, we create a class called SecureLocalStorage that takes a secretKey as a constructor parameter. This secretKey is used for encrypting and decrypting the data using the Advanced Encryption Standard (AES) algorithm.

The class provides the following methods:

  • encrypt(data): Encrypts the provided data using AES encryption and the secretKey.
  • decrypt(encryptedData): Decrypts the provided encrypted data using AES decryption and the secretKey.
  • store(key, data): Encrypts the data and stores it in the localStorage with the specified key.
  • retrieve(key): Retrieves the encrypted data from localStorage using the key, decrypts it, and returns the original data.
  • remove(key): Removes the data associated with the specified key from localStorage.

Please note that this example requires the CryptoJS library to perform encryption and decryption using AES. Make sure to include the CryptoJS library in your project before using this class.

Here’s an example usage of the SecureLocalStorage class:

// Create an instance of SecureLocalStorage with a secret key
const secureStorage = new SecureLocalStorage('mySecretKey');

// Store data in localStorage
const data = { username: 'johnDoe', email: '' };'userData', data);

// Retrieve and decrypt data from localStorage
const retrievedData = secureStorage.retrieve('userData');
console.log(retrievedData); // { username: 'johnDoe', email: '' }

// Remove data from localStorage

In this example, we create an instance of SecureLocalStorage with the secret key 'mySecretKey'. We then store a sample data object using the store method and retrieve it using the retrieve method, which automatically decrypts the data. Finally, we remove the stored data using the remove method.

Remember to use a strong and secure secret key to ensure the confidentiality of the encrypted data.