My Book Live Password Protection

Hi,  Last night I purchased a new 3TB My Book Live and I am currently in the process of transferring my files to the new drive.  However, I am using the drive in a shared house where other people have access to the router, is there any way I can password protect the device so only I can access the files contained within.  I have set up a private area but it appears the public area is open to all.  Many thanks

Don’t use the public share, then.  ;)