/**
* Encrypt a string
*
* @param string $plaintext
* @return string
*/
public function encrypt($plaintext)
{
$nonce = \Sodium::randombytes_buf(\Sodium::CRYPTO_SECRETBOX_NONCEBYTES);
$encrypted = \base64_encode($nonce . \Sodium::crypto_secretbox(\json_encode($plaintext), $nonce, $this->key->getKey()));
\Sodium::memzero($plaintext);
return $encrypted;
}
