What are the potential security risks of using base64 encoding for encryption in PHP?

Using base64 encoding for encryption in PHP is not secure because it is not encryption, but rather just an encoding scheme. It can be easily decoded and does not provide any real security for sensitive data. To properly encrypt data in PHP, you should use a secure encryption algorithm like AES.

// Encrypt data using AES encryption
function encryptData($data, $key) {
    $iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length('aes-256-cbc'));
    $encrypted = openssl_encrypt($data, 'aes-256-cbc', $key, 0, $iv);
    return base64_encode($iv . $encrypted);
}

// Decrypt data using AES decryption
function decryptData($data, $key) {
    $data = base64_decode($data);
    $iv = substr($data, 0, openssl_cipher_iv_length('aes-256-cbc'));
    $encrypted = substr($data, openssl_cipher_iv_length('aes-256-cbc'));
    return openssl_decrypt($encrypted, 'aes-256-cbc', $key, 0, $iv);
}

// Example usage
$key = 'secret_key';
$data = 'Hello, world!';
$encryptedData = encryptData($data, $key);
echo "Encrypted data: " . $encryptedData . "\n";
echo "Decrypted data: " . decryptData($encryptedData, $key);