How to encrypt and decrypt JSON data in JavaScript.

24 Sep 2023

In today’s interconnected world, data security is of utmost importance. Encrypting sensitive data is a common practice to protect it from unauthorized access. In this blog post, we will explore how to encrypt and decrypt JSON data in JavaScript using a popular encryption algorithm.

Prerequisites

Before we begin, make sure you have the following:

Basic knowledge of JavaScript
Text editor or an integrated development environment (IDE)
Web browser to execute and test JavaScript code

Step 1: Set up the Encryption Algorithm

First, we need to choose an encryption algorithm. In this example, we will use the Advanced Encryption Standard (AES) algorithm, which is widely used for secure data transmission.

To use AES encryption in JavaScript, we will use a library called CryptoJS. You can include it in your project by downloading the library from the official website or by using a package manager like npm.

Step 2: Encrypt JSON Data

To encrypt JSON data, follow these steps:

Convert the JSON data to a string.
Generate a secret key or passphrase.
Use the CryptoJS library to encrypt the JSON string with the generated secret key.

Here’s an example code snippet that demonstrates the encryption process:

const json = { "name": "John Doe", "age": 30 };
const jsonString = JSON.stringify(json);

const secretKey = "mySecretKey123";
const encryptedData = CryptoJS.AES.encrypt(jsonString, secretKey).toString();

In the code above, we convert the JSON object to a string using JSON.stringify(). Next, we generate a secret key, which should be kept securely. Finally, we use the CryptoJS.AES.encrypt() method to encrypt the JSON string with the secret key. The encrypted data is stored in the encryptedData variable.

Step 3: Decrypt the Encrypted Data

To decrypt the encrypted data, follow these steps:

Use the same secret key or passphrase used for encryption.
Use the CryptoJS library to decrypt the encrypted data back to a JSON string.
Parse the decrypted JSON string back into a JavaScript object.

Here’s an example code snippet that demonstrates the decryption process:

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

In the code above, we use CryptoJS.AES.decrypt() to decrypt the encrypted data using the secret key. The decrypted data is stored in decryptedBytes. We then convert the decrypted bytes to a string using toString(CryptoJS.enc.Utf8) and parse it back into a JavaScript object using JSON.parse(). The resulting object is stored in decryptedData.

Conclusion

Encrypting and decrypting JSON data in JavaScript using the AES algorithm provides an additional layer of security for sensitive information. By following the steps outlined in this blog post, you can ensure that your data remains protected during transmission or storage.

Remember to always store the secret key or passphrase securely and avoid exposing it to unauthorized access.