BEE was designed to run on a shared hosted environment.  That means web sites from different owners may run on the same network or even the same machine.  It is therefore crucial to make sure the hosted web sites can only access the resources they are designated to and nothing else, so that they will not intervene with each other and no privacy will be breached.  To the web site, the platform and the resources are contained in a "black-box", and no knowledge of them needs to be of concern to the codes.

Here are the main design criteria derived from the Black-box Principle:

• A web page cannot access any databases except for the ones designated.
• Database operations must not be affected by the choice of the database platform and its location.  Subsequent changes of such choices must not require any code changes.