I have a client, for which I'm going to do an Web application about patient care, managing patients, consults, history, calendars, everything about that basically.

The problem is that this is sensitive data, patient history and such.

The client insists on encrypting the data at the database level, but I think this is going to deteriorate the performance of the web app. ( But maybe I shouldn't be worried about this )

I've read the laws about data protection on health issues ( Portugal ), but isn't very specific about this ( I just questioned them about this, I'm waiting for their response ).

I've read the following link, but my question is different, should I encrypt the data in the database, or not.

One problem that I foresee in encrypting data, is that I'm going to need a key, this could be the user password, but we all know how user passwords are ( 12345 etc etc ), and generating a key I would have to store it somewhere, this means that the programmer, dba, whatever could have access to it, any thoughts on this?

Even adding an random salt to the user password isn't going to solve the problem since I can always access it, and therefore decrypt the data.