[pinkythepig]

As soon as you walk by someone or shake someones hand, they can copy your implanted RFID. Now, if you want to 'change the locks' to your house and car, you will need to dig out the chip in your hand and implant a new one.

To me, adding the capability to a watch, fitbit or other such wrist wearable is the far more practical option. Easy to change out if it gets compromised, plus you can build in a switch so that it is only capable of broadcasting when you press a button.

[noxToken]

You're only thinking from a security standpoint. It's valid, but there can be other goals for the system. You can take off a watch to leave at your desk. You probably don't want to chop off a finger.