In a situation where an admin will enter sensitive information into a keyboard (the root password), what is the risk that a bluetooth keyboard (ship by default with Mac systems these days) would put those passwords at risk?

Another way of asking would be: what security and encryption protocols are used, if any, to establish a bluetooth connection between a keyboard and host system?

Edit: Final Summary

All answers are excellent. I accepted that which links to the most directly applicable information however I also encourage you to read Nathan Adams's response and discussion about security trade-offs.

I have inherited a server that is a Virtuozzo guest. I just noticed that /usr/bin/free is reporting 100% or near-100% memory usage; no shared, no buffers, no cache:

# free -m
             total       used       free     shared    buffers     cached
Mem:          4045       4045          0          0          0          0
-/+ buffers/cache:       4045          0
Swap:            0          0          0

All services are responsive. Both top and ps do not show any processes nearly close to 4GB of allocated memory.

Not to jump the gun but I've managed many Linux systems seen this situation. I vaguely remember reading that Virtuozzo has a dynamic over-committed memory management system, so I was wondering if that is it, and the striking results above are not cause for alarm.

Or should I begin to panic?

Update

For the record, it turned out that a process was definitely consuming memory. It wasn't an artifact of Virtuozzo.

Main Task

What is the procedure for dumping a VirtualBox system? Note that this is not migrating the guest OS from hardware to virtualization or anything else mentioned by Googling "migrate virtualbox". I mean:

• Moving all guest data (virtual drives, snapshots, etc) onto external media or remote storage
• Being able to confidently and completely delete that data from my system
• From a different system with VirtualBox installed, being able to fetch the guest data, write it to the local storage, and boot it up.

I suspect that the backing up part is straightforward enough; but the restoration may require manual edits of the XML config files via some well-defined process. I'd love to know that process.

Bonus points

• I am on Linux, but a platform-independent solution would be great too. Hell, even a Windows solution would be a decent starting point.
• If the solution supports dissimilar installation and data directories, that would be cool. But if not, I can accept the requirement that both systems use identical paths for VirtualBox directories
• Support for dissimilar host hardware (specifically Ethernet) might be nice, but is not terribly important for me.

Well, any ideas? I will upvote partial solutions which point me in the right direction.