How can encryption techniques like blowfish be used to enhance the security of cookies in PHP applications?

Cookies in PHP applications often store sensitive information that can be intercepted or tampered with by malicious users. By using encryption techniques like Blowfish, we can secure the data stored in cookies by encrypting it before setting the cookie and decrypting it when retrieving the cookie value. 

// Set the cookie with encrypted data
$encryptionKey = "YourEncryptionKeyHere";
$data = "sensitive_data_to_encrypt";
$encryptedData = openssl_encrypt($data, 'BF-CBC', $encryptionKey, 0, 'YourIVHere');
setcookie('secure_cookie', $encryptedData, time() + 3600, '/');

// Retrieve the cookie and decrypt the data
if(isset($_COOKIE['secure_cookie'])){
    $encryptedData = $_COOKIE['secure_cookie'];
    $decryptedData = openssl_decrypt($encryptedData, 'BF-CBC', $encryptionKey, 0, 'YourIVHere');
    
    // Use the decrypted data as needed
    echo $decryptedData;
}

Related Questions