Hiding galleries from specific users in Gallery2

Hi Gallery2,

Before I start installing Gallery2, it'd be a real help if someone could shed some light on the following....

Say I have 2 clients, Client 1 & Client 2. I want Client 1 to go to a sub-domain I've created with Gallery2 installed, and be presented with a login panel (username & password required). Correct entry of username and password takes Client 1 into his gallery (Client1Gallery) so he can view the images in it but have no idea there is another gallery for Client 2 (Client2Gallery) in the same subdomain.

Essentially both clients should only be able to see their gallery after login (as opposed to being able to see both galleries but being denied access to one of them).

Would I need to install Gallery2 in 2 separate directories to make this work, or can Gallery hide certain galleries in a single directory based on user ID?

Many thanks in advance for your time.

Chris