Sandy says:

POISON PILL--What, if anything, can be done to booby-trap a computer? Once the cops have a machine, one would expect that they will paw through everything in it. In addition, they will probably use the stolen computer for their own data processing needs. What could be done have the computer screw up the cop's data days, weeks or months after the seizure? Of course, I would never do such a thing myself, nor would I advise anyone else to do so.

Why wouldn't you? Its your machine, so what you do to it is perfectly legal. You are under no obligation to make your equipment suitable for people who wish to steal it. Nothing you can do in software will actually work, because people can always boot off a fresh disk and start from scratch. I suggest that the best way, which is not easy, is to alter the roms on the disk controllers so they will only work properly with a special version of the operating system. Then, run the special version of the operating system, which should require that you do something periodically or it will self destruct. Even if they reformat the disk, they still won't have the proper information to feed the controller so that it doesn't do unfortunate things. Perry

In reply to (Sandy): | POISON PILL--What, if anything, can be done to booby-trap a | computer? Once the cops have a machine, one would expect that | they will paw through everything in it. In addition, they will | probably use the stolen computer for their own data processing | needs. What could be done have the computer screw up the cop's | data days, weeks or months after the seizure? Of course, I would | never do such a thing myself, nor would I advise anyone else to | do so. I do, however, have a passing academic interest in the | subject. Same for you folks too, right? How about this: Encrypted disk controller that uses 3DES (at a minimum) where the keys are modified by a low power localised RF transmission. Quite simply one could use a DDS receiver which looks at any one of X locations for a signal strength above some threshold (ie, say 2^16 frequency slots and only 3 * 56 of these are transmitting), this provides the XOR for the DES key. In fact, one could almost patch this into an existing DES controller given some assumptions about the onboard logic. Your transmitter should be like somewhere else in your flat, preferably hidden. Of course, once the feds get your computer and it doesn't work, they will ask you why, and you need some way here to keep them off. Actually, another idea, how about if the DES key(s) for your controller are hardwired onto it, an RF detector monitors a carrier on some specific frequency, if the carrier is not present at bootup, you could leak a high voltage into the 'key holder' and blow all the connected links. Once this is gone, there is no way to get back the data, and the feds can't force you, because 1) you can show how the key was random in the first place 2) you can show how the device blew it all (and that there was no return), and your justification can be for 'data security' reasons (ie, if theives get your system, they couldn't have extracted anything). They could probably example the chip substrate itself and see what was blown recently, so this needs work I guess. Another problem is that the above assumes they don't examine the disk, realise it is encrypted, realise the controller is custom, and then work back to figure out what is going on, and then question you before they do anything. Disclaimer: the above represents unsubstantiated theorising. Matthew. ps; when the feds take your computer (at least here in Australia) they take lots of nice pictures of it and take all the cables and stuff. Of course, half of them don't know the fucking difference between msdos and unix. -- Matthew Gream, M.Gream@uts.edu.au. "... encryption is the ultimate means of Consent Technologies, 02-821-2043. protection against an Orwellian state."