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BusKill: A kill cord for your laptop

tech.michaelaltfield.net

121–130 of 272 posts

Re: BusKill: A kill cord for your laptop

#122
post #16

Archive link because the website is down: http://web.archive.org/web/20200102140351/https://tech.micha... I was expecting a "kill switch" destroying the computer, but that's just a thing that switch off your laptop when unplugged. I guess you could also do this with bluetooth, for example.

If you are doing proper OpSec, you would have whole disk encryption anyway, in which case destroying the computer is largely unnecessary, I think. That said, the caveat of XKCD 538 ( https://www.xkcd.com/538/ ) still applies.

Good opsec blends into the crowd.

If the FBI traces illegal activity to a cafe / library / wework office, and you're the only one with a kill cord attached to your belt with a carabiner, guess who they're going to target first.

Re: BusKill: A kill cord for your laptop

#123
post #104

Earlier quoted context omitted.

Ross Ulbricht would like to have a word with you.

they snatched his computer while it he was using it - open and unlocked

Indeed. My point is he had full disk encryption and password at boot and it didn’t stop the govt from accessing his data.

Re: BusKill: A kill cord for your laptop

#124
post #104
post #33

Earlier quoted context omitted.

I suppose if the drive is encrypted and requires a passphrase at boot, it's effective for FBI raids, etc.

Ross Ulbricht would like to have a word with you.

Two undercover agents distracted him while a third snatched his running and logged-in laptop. https://www.businessinsider.com/the-arrest-of-silk-road-mast...

That sounds like exactly a good use case for this. Or maybe that's what you meant?

Re: BusKill: A kill cord for your laptop

#125
post #123

Earlier quoted context omitted.

they snatched his computer while it he was using it - open and unlocked

Indeed. My point is he had full disk encryption and password at boot and it didn’t stop the govt from accessing his data.

It was logged in and running when they snatched it. Hence why a breakaway mag connector and dead-man shutdown script might have been helpful.

Re: BusKill: A kill cord for your laptop

#126
post #79

Earlier quoted context omitted.

I've always heard that cold boot attacks like that require the ram to be frozen before the computer turns off (or the ram is removed).

In reality, RAM doesn't so much instantly lose its contents on power off anyway, the freezing just slows it down. IIRC there are cases of recovering significant portions of RAM a half hour or more after poweroff even without freezing.

You're right, I think an attack could be possible on some computers if the agents act very quickly. I don't think 30 minutes would be possible though, judging from what is said and shown in the original cold boot video:

https://www.youtube.com/watch?v=JDaicPIgn9U

Re: BusKill: A kill cord for your laptop

#128

Earlier quoted context omitted.

If you happen to have an opinion that is not shared by the current powers-that-be, law enforcement will be happy to look at your data under any pretense it can cook up. And they'll be equally fine with - ooops! accidentally, of course! - leaking info that you'd like to stay hidden, even if it's not anything criminal.

In other words, it's just a bunch of self-important tech asshats deluding themselves into believing they are important enough to warrant FBI attention? Eh, believable, but I think it's more likely a lot of them are evading taxes or committing securities fraud.

I would probably look into it if I was already on some government agency's radar for whatever reason. You've probably broken a ton of obscure laws yourself without knowing it.

Re: BusKill: A kill cord for your laptop

#129
post #34
post #16

Earlier quoted context omitted.

If you are doing proper OpSec, you would have whole disk encryption anyway, in which case destroying the computer is largely unnecessary, I think. That said, the caveat of XKCD 538 ( https://www.xkcd.com/538/ ) still applies.

I'm surprised there isn't a "ready to go" solution with a duress passphrase that boots a plausible, but "clean" system.

you'll still have to explain why there is a huge blob of seemingly random data on your hard drive if someone looks close enough.

Re: BusKill: A kill cord for your laptop

#130
post #17

Saw a demo 20 years ago at Infosec(UK) of a company selling a dongle which with corresponding pass, acted as a proximity authentication and locking when you walked away. Today, most laptops have cameras which can offer the same level of proximity detection if you away from the laptop. That would make this type of solution doable via software that way, albeit a bit more of a software load overhead. But for some killco…

> most laptops have cameras which can offer the same level of proximity detection Most people who would want a kill cord probably have the camera blocked :P

If that kill cord actually killed the laptop/drive over just shutting it down, I'd tend to agree.
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