I know bluetooth supports encryption, but is it in use? How do I know?
The help in the Bluetooth preference pane gives some vague answers:
For extra security, you can stipulate that only trusted devices be allowed to connect to your Mac, and 128-bit over-the-air encryption is also available.
But I don't see any options like what they just said.
Nothing on the Apple Store's product description for the Magic Trackpad says anything about encryption. Same for Amazon. Same for the Apple Support pages.
Maybe it's encrypted and Apple thinks that's just obvious, so they don't waste time telling you it is, but I'm looking for evidence.