3 ms·
I've often thought about this, but came to the opposite conclusion: a laptop is the smallest thing you can trust. The keyboard sends data to the CPU. The CPU
by spin 11y ago
I've often thought about this, but came to the opposite conclusion: a laptop is the smallest thing you can trust. The keyboard sends data to the CPU. The CPU sends data to the screen. The CPU does encryption and talks to the network.
I feel like there's no point in trying to chop it down any smaller than that. All you're doing is shifting trust from "system A" to "system B", without really changing anything.
- Gibbon1 11y agoThe keyboard has a CPU that can do encryption and signing, in addition to decoding for key presses. Ditto for touch screens. The reason for putting the encryption in system B AKA the keypad and display controllers is, if you want end to end encryption, the keypad decoder and the display controller are the closest to the end points you can get. And they are single purpose devices that don't run arbitrary code nor accept arbitrary input. Compare that with laptop CPU's and complex operating systems with their huge attack surfaces. Running software written by completely untrustworthy corporations and individuals.
- leni536 11y ago> And they are single purpose devices that don't run arbitrary code nor accept arbitrary input. But be careful designing firmware upgrades though. Also I really don't see what kind of attack it prevents when you have a trusted keyboard and display but otherwise compromised OS.