Comment Re:How About Bluetooth Keyboards (Score 1) 85
Bluetooth 2.1 and up are pretty good security wise, links are always encrypted and pairing with SSP can also protect you from an MITM attack. (e.g. using numeric comparison or passkey entry is secure from MITM. See the relevant wikipedia page for specifics.)
Since encryption is required (and usually done in dedicated hardware), there shouldn't be a difference in battery life.