Encrypted File Server

[BinaryOutlaw]

Ok so what I want is a linux file server that can serve up files to users on Windows, Mac, and
Linux. I want the request and transmission of said files to be encrypted, ideally with a key file for maximum security. Also the system needs to be relatively easy to access. A lot of my friends and family I wish to share videos, pictures, documents, and other files with are not skilled with computers, ie needs to be GUI on their end.

Not too new to Linux, I run Ubuntu 12.04 built from command line via their mini.iso. Even made a .sh script file to simplify and speed up reformatting after screwing with something I shouldn't have. ( I compulsively fiddle with things. )

I am however pretty new to file servers, I have done some research but I am in need of help. My only experience is a bit of fiddling with a simple FTP client on Windows.

Please help.

[HROAdmin26]

There is "data at rest" encryption and "data in transmission" encryption. You have said you are only concerned with transmission:

request and transmission of said files to be encrypted

You can host your files via SSL-enabled webserver, IE, clients would only need to access an https:// webpage. No other GUI/software is needed on the client side.

[BinaryOutlaw]

What do you mean by data at rest? Disk encryption? I would like to make it more private then that though. I don't want just anyone accessing the server. Anyway to make an https webserver more secure?

[HROAdmin26]

Put a password on it?

Google: apache password htaccess => Example