Helper class to create RSA keys, encrypt and decrypt data with public and private key

Encryption.php

class Encryption
{
    private $path = 'CUSTOM PATH';    

    public static function generateKeys()
    {
        $privateKey = openssl_pkey_new(array(
            'private_key_bits' => 2048,      // Size of Key.
            'private_key_type' => OPENSSL_KEYTYPE_RSA,
        ));

        // Save the private key to private.key file. Never share this file with anyone.
        openssl_pkey_export_to_file($privateKey, self::$path . '/rsa/id_rsa');

        // Generate the public key for the private key
        $a_key = openssl_pkey_get_details($privateKey);
        // Save the public key in public.key file. Send this file to anyone who want to send you the encrypted data.
        file_put_contents(self::$path . '/rsa/id_rsa.pub', $a_key['key']);

        // Free the private Key.
        openssl_free_key($privateKey);
    }

    public static function encrypt($value)
    {
        // Compress the data to be sent
        $plaintext = gzcompress($value);

        // Get the public Key of the recipient
        $publicKey = openssl_pkey_get_public('file://' . self::$path . '/rsa/id_rsa.pub');

        $a_key = openssl_pkey_get_details($publicKey);

        // Encrypt the data in small chunks and then combine and send it.
        $chunkSize = ceil($a_key['bits'] / 8) - 11;
        $output = '';

        while ($plaintext) {
            $chunk = substr($plaintext, 0, $chunkSize);
            $plaintext = substr($plaintext, $chunkSize);
            $encrypted = '';
            if (!openssl_public_encrypt($chunk, $encrypted, $publicKey)) {
                die('Failed to encrypt data');
            }
            $output .= $encrypted;
        }
        openssl_free_key($publicKey);

        return $output;
    }

    public static function decrypt($encrypted)
    {
        // Get the private Key
        if (!$privateKey = openssl_pkey_get_private('file://' . self::$path . '/rsa/id_rsa')) {
            die('Private Key failed');
        }
        $a_key = openssl_pkey_get_details($privateKey);

        // Decrypt the data in the small chunks
        $chunkSize = ceil($a_key['bits'] / 8);
        $output = '';

        while ($encrypted) {
            $chunk = substr($encrypted, 0, $chunkSize);
            $encrypted = substr($encrypted, $chunkSize);
            $decrypted = '';
            if (!openssl_private_decrypt($chunk, $decrypted, $privateKey)) {
                die('Failed to decrypt data');
            }
            $output .= $decrypted;
        }
        openssl_free_key($privateKey);

        // Uncompress the unencrypted data.
        return gzuncompress($output);
    }
}