Use an AEAD. Learn that PHP doesn't support an AEAD. Wait for PHP 7.1... I recently covered this a bit when I looked at owncloud's crypto: https://blog.hboeck.d

Use an AEAD. Learn that PHP doesn't support an AEAD. Wait for PHP 7.1... I recently covered this a bit when I looked at owncloud's crypto: https://blog.hboeck.de/archives/880-Pwncloud-bad-crypto-in-the-Owncloud-encryption-module.html https://blog.hboeck.de/archives/880-Pwncloud-bad-crypto-in-t... The situation is far from ideal. Recommending libsodium-php is also not as simple, as this requires an additional thing to be installed on a server, which probably isn't the case for most shared hosting environments.