3 ms·

Love these kinds of problems. I've always felt for very critical equipment you'd be better off designing a PCB to be physically cracked in two, such that you n

Love these kinds of problems. I've always felt for very critical equipment you'd be better off designing a PCB to be physically cracked in two, such that you need both specific halves for it to operate at all, and then ship each half separately. E.g. the electronics version of tearing a dollar bill in half and matching the two halves to verify the identity of the holder (something I've seen in spy movies). You'd probably want to make sure the recipient got the first part before shipping the second, just to make sure.

dlgeek 4y ago
Wouldn't help if the chips on the PCB could be replaced.
poyu 4y ago
All modern credit card terminals have this built in. It has a mainboard/sub-board design. In case one or more contacts has been apart, the contents (assuming some kind of keys) on the sub-board are erased, something like a SRAM. Downside is it needs constant power source to keep the content, thus a rechargeable cell is on the board.
- wildzzz 4y ago
  Crypto devices used by the government and military have this same sort of tamper identification design. I've seen limit switches hidden behind the front lip of a server so if you pull it out, it triggers the tamper alarm. There are also panels with multiple switches behind so if the panel is opened, alarm triggers. There's layered mesh inside the walls of the devices that will trip the alarm if the layers touch (like with a drill) or if the voltage going through the mesh layer changes (like if you cut through it). Once any seals are broken, the keys inside are wiped and the device is possibly bricked if it really was never meant to be opened. Additionally, screws are JB welded in place so only way you can get in is to either go through the access panel or drill a hole. These things are tempest rated so no one is getting in and nothing is coming out, unless of course you manage to hack it without ever touching it.

dlgeek 4y ago

Wouldn't help if the chips on the PCB could be replaced.

poyu 4y ago

All modern credit card terminals have this built in. It has a mainboard/sub-board design. In case one or more contacts has been apart, the contents (assuming some kind of keys) on the sub-board are erased, something like a SRAM. Downside is it needs constant power source to keep the content, thus a rechargeable cell is on the board.

wildzzz 4y ago
Crypto devices used by the government and military have this same sort of tamper identification design. I've seen limit switches hidden behind the front lip of a server so if you pull it out, it triggers the tamper alarm. There are also panels with multiple switches behind so if the panel is opened, alarm triggers. There's layered mesh inside the walls of the devices that will trip the alarm if the layers touch (like with a drill) or if the voltage going through the mesh layer changes (like if you cut through it). Once any seals are broken, the keys inside are wiped and the device is possibly bricked if it really was never meant to be opened. Additionally, screws are JB welded in place so only way you can get in is to either go through the access panel or drill a hole. These things are tempest rated so no one is getting in and nothing is coming out, unless of course you manage to hack it without ever touching it.