Yes, you can give credit to whoever you choose, just by inputing their name. No passwords or anything. It's based on the premise that if you care about credits, the worst that can happen is someone misusing your name to ... give you more credits.
BOINC, a distributed computing program for Windows, Unix-like OSes (not sure about Apple) does allow password protection, but that is also because your password also allows you to set perametres under which all your computers will deal with WUs (such as how much CPU % or RAM % to devote.)







