BusKill: A kill cord for your laptop • Hacker News Board

Re: BusKill: A kill cord for your laptop

#91

Post by amelius » Thu, Jan 02, 2020, 5:17 PM UTC

dangus wrote: post #29

This is a really neat project but it’s also not really a solution to anything. First, it doesn’t solve for the scenario of person pointing a gun at you and telling you to access your top secret files for them. That will defeat most forms of security and so if physical access is a concern you probably shouldn’t be logging in at your local coffee shop. Second, a thief who wants your computer for its monetary value isn’…

> Second, a thief who wants your computer for its monetary value isn’t interested in its contents.

They could blackmail you, sending you an email with a bitcoin address you should transfer money to or else the data will go public.

Re: BusKill: A kill cord for your laptop

#92

Post by Jamwinner » Thu, Jan 02, 2020, 5:21 PM UTC

michaelt wrote: post #27

Reventlov wrote: post #4

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.

"Kill cord" is jargon from jetskis, powerboats and treadmills, which often have a cord you attach to your body that cuts power if you are thrown off. [1] On Linux there is blueproximity [2] that can lock (and if you like, unlock) your computer based on the proximity of a bluetooth device. My personal experience is that Bluetooth is frustratingly unreliable, and this package was no exception. But it's there if you'd l…

I used blueprox for years with no fuss. Might try a different bt dongle.

Re: BusKill: A kill cord for your laptop

#93

Post by AnIdiotOnTheNet » Thu, Jan 02, 2020, 5:22 PM UTC

ShakataGaNai wrote: post #76

savingGrace wrote: post #53

Another solution would be to just remove the battery and plug the laptop in. While this removes the portability, it is still an alternative solution.

Maybe a decade or so ago this would be a good answer. But unless you're one of those ThinkPad people who are still pulling for the X220 to make a come back.... A majority of modern laptops don't have user removable batteries. Yes, they could still be removed in some cases, but its often not for the feint of heart and not something many people would want to undertake.

> A majority of modern laptops don't have user removable batteries.

Yet another major regression in the state of computing since the 90s.

Re: BusKill: A kill cord for your laptop

#94

Post by miles » Thu, Jan 02, 2020, 5:30 PM UTC

Windows users may want to try the built-in Bluetooth proximity locking feature:

Lock your Windows 10 PC automatically when you step away from it https://support.microsoft.com/en-us/help/4028111/windows-loc...

While macOS doesn't include such a feature out of the box, apps like Near Lock https://nearlock.me exist.

EDIT: Just found Rohos Logon Key for Windows and macOS:

https://www.rohos.com/products/rohos-logon-key-for-mac/

It "converts any USB drive into a security token for your computer" and can "automatically lock your Mac screen when the key is unplugged".

Re: BusKill: A kill cord for your laptop

#95

Post by dbtx » Thu, Jan 02, 2020, 5:30 PM UTC

  echo o > /proc/sysrq-trigger

(read linux/Documentation/admin-guide/sysrq.rst before you try this)

Re: BusKill: A kill cord for your laptop

#96

Post by s_gourichon » Thu, Jan 02, 2020, 5:35 PM UTC

dbtx wrote: post #95

echo o > /proc/sysrq-trigger (read linux/Documentation/admin-guide/sysrq.rst before you try this)

shutdown -h now or the more recent incantation (from memory) systemctl shutdown would be less violent. AFAIK it can't be stopped either, and at least it sync's and umount's filesystems properly.

Re: BusKill: A kill cord for your laptop

#97

Post by michaelt » Thu, Jan 02, 2020, 5:36 PM UTC

hutzlibu wrote: post #81

michaelt wrote: post #27

Earlier quoted context omitted.

"Kill cord" is jargon from jetskis, powerboats and treadmills, which often have a cord you attach to your body that cuts power if you are thrown off. [1] On Linux there is blueproximity [2] that can lock (and if you like, unlock) your computer based on the proximity of a bluetooth device. My personal experience is that Bluetooth is frustratingly unreliable, and this package was no exception. But it's there if you'd l…

Is it possible that the bluetooth unreliability was a driver issue and others work fine? In other words, did you test different bluetooth devices?

I only tested with my smartphone, as it's the only bluetooth device I reliably carry with me.

I'm sure there are configurations that work - blueproximity probably worked well for its author, or they wouldn't have released it! And I gather Windows offers "Dynamic lock" which locks the screen based on bluetooth.

However, having experienced bluetooth unreliability with Linux, Windows, Android and iPhone; and with mice, GPS receivers, cars, access control systems and sports watches; I am confident the unreliability was not unique to a single bluetooth device.

Re: BusKill: A kill cord for your laptop

#98

Post by mlinksva » Thu, Jan 02, 2020, 5:38 PM UTC

sysbin wrote: post #7

Maybe a smartwatch reading the heart rate of the owner and noticing stimulation could trigger the same functionality as well.

Do any phones have a tether like this? Or use some other mechanism to guess that possession may have changed and autolock?

Re: BusKill: A kill cord for your laptop

#99

Post by tyingq » Thu, Jan 02, 2020, 5:43 PM UTC

AnIdiotOnTheNet wrote: post #90

tyingq wrote: 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.

Whenever I read stuff like this I am forced to wonder just what the fuck people are doing that they feel such a pressing need to hide their data from law enforcement. I mean, I have plenty of things to hide just like any other reasonably interesting person, but none of it is outright criminal.

There's no shortage of things someone might find morally acceptable themselves while still being potentially criminal. Or grey area stuff, like a business that sells marijuana in a state where it's legal, since the US federal government doesn't consider it legal.

Or use cases like a crypto wallet. Where legality isn't the main concern.

Re: BusKill: A kill cord for your laptop

#100

Post by jlg23 » Thu, Jan 02, 2020, 5:46 PM UTC

austhrow743 wrote: post #83

k_sze wrote: 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.

Are there any known cases of western police forces beating people with wrenches until they gave up passwords?

A few months in prison for not revealing the password can be unpleasant, too.