Analogous thing happens when you start the engine. The key has
a Philips transponder, offering 128 Bytes of rw memory. After key
ID is written, this segment's write protection bit is turned on.
Irreversibly. Codes issued, icbms in transit, all fucked.
The key contains a key, a random token. Using a hardware random
(a free-running counter with a couple of extra mangling) a
new token in generated, and written into the transponder. Each
time you use your key, lest flash/E^2 oxide layer abandon ye.
If you want to start your car, and the token within the EWS and
the key won't match, the engine won't start. Awwww. The unit
knows a subspace of 10 keys, having inherited it from a central
dbase (so don't lose your keys too often, it might require a
visit at Joe's). And of course one can't read systems's memory
by diagnosis packets over the bus. Orelse this would be too simple.
This is not sf, btw. Just a high-end limousine extra.
to your Datsun. (Attention: here comes the sf part).
Consider implanting a bionert trasponder implant into your wrist. Not his
master's voice, his master's touch. TACK. Next, please. (Though you might
consider this to be large horned male bovine excrement, many members of
the abovementioned tribe already wear transponder emplants (and it even
were't the Greys)).
Each device you own now knows you. Intimately. Either rendering
unauthorized use impossible (why not by void SYS_detonate()? (of
_course_ void. Which return value if there is nothing to return
to?)), or instantly coming up with your customized environment,
for multi-user devices. Useful, eh?
Then comes the guy with katana and a plastic sack, and you've
lost your keys. _And_ your arms. (Both, for the guy does not
know what your dominant arm is). Shit. Shit. Shit. And no clone
Hmm... How about a piezo crystal in the transponder? You tap the
code (which even generates piezojuice), and lock/unlock the
particular key(s) from a ring. (If you walk around with all your
keys armed, you certainly deserve what happens to you). Or consider
making a biosig fingerprint part of key. Retina, finger, voice,
mugshot. "Kindly place your palm on the rectangular window,
gazetrack the 3cursor, and repeat after me: Betty Botter...
No, sorry, I _cannot_ let you drive your car. Your sonogram
says you are hoarse, and mass-spectro of your breath indicates
presence of ethanol breakdown metabolites. Residual alcohol
level estimate gained from your body mass (you gained weight
since yesterday, _again_) says your reaction latency to be
sufficiently inhibited to render you incapable for car driving.
Have a nice day."
(Of course there is torture. But there is no perfect security,
and one can always consider zeroing the flash by means an
biofeedback-learned EEG signal. Ok, this means one must render
your unconscious (by whatever means) asap, but there _is_ no
perfect security. Did I already say that?).