Cloud combined with an internal database. What is the safety of security?


I'm currently performing a research on cloud computing. I do this for a company that works with highly private data, and so I'm thinking of this scenario:

A hybrid cloud where the database is still in-house. The application itself could be in the cloud because once a month it can get really busy, so there's definitely some scaling profit to gain. I wonder how security for this would exactly work.

A customer would visit the website (which would be in the cloud) through a secure connection. This means that the data will be passed forward to the cloud website encrypted. From there the data must eventually go to the database but... how is that possible?

Because the database server in-house doesn't know how to handle the already encrypted data (I think?). The database server in-house is not a part of the certificate that has been set up with the customer and the web application. Am I right or am I overseeing something? I'm not an expert on certificates and encryption.

Also, another question: If this could work out, and the data would be encrypted all the time, is it safe to put this in a public cloud environment? or should still a private cloud be used?

Thanks a lot!! in advance!!

Kind regards,


The secure connection between the application server and the database server should be fully transparent from the applications point of view. A VPN connection can connect the cloud instance that your application is running on with the onsite database, allowing an administrator to simply define a datasource using the database server's ip address.

Of course this does create a security issue when the cloud instance gets compromised.