Nelmio\SecurityBundle\Encrypter::encrypt PHP Метод

    public function encrypt($input)
    {
        if (empty($input)) {
            return;
        }
        $iv = mcrypt_create_iv($this->ivSize, MCRYPT_RAND);
        mcrypt_generic_init($this->module, $this->secret, $iv);
        return rtrim(base64_encode($iv . mcrypt_generic($this->module, (string) $input)), '=');
    }

 public function testEncryption()
 {
     $encrypter = new Encrypter('secret', 'rijndael-128');
     $value = 'bar';
     $encryptedValue = $encrypter->encrypt($value);
     $this->assertNotEquals($encryptedValue, $value);
     $decrypted = $encrypter->decrypt($encryptedValue);
     $this->assertEquals($decrypted, $value);
 }