
226 CHAPTER ELEVEN
RFID may again be a key technology in making amorphous and ubiquitous computing
practical. A person may carry an RFID tag containing an encryption key that allows her,
upon entering an office or entertainment room, to authenticate herself to the systems
embedded in the walls and furniture with an additional password and biometric scan. The
RFID tag then becomes the “something you have” in the security triad of “something you
know, something you are, and something you have.”
Candidates for the “killer app” can usually be identified only in retrospect. The killer app
for Apple II was the VisiCalc spreadsheet; the jury is still out on whether email or the web
browser has been the killer app for the Internet. But even in the misty past prior to 1990,
there were those who suggested that hypertext might be pretty important someday. With
their luck in mind, we will try here to peer into the future of RFID and describe what we
see. Both of the sections below describe applications for which prototypes already exist.
Micro payments
As mentioned before, RFID could be a key enabler for ubiquitous computing. We talked
about how it could be used to provide IDs for authentication, but there are other ways
RFID could be critical to making these technologies work. Not long ago, driving home
from work, you wouldn’t have been likely to call home to let your family know when to
expect you. Too much ...