BusKill – A USB kill cord for laptops • Hacker News Board

Re: BusKill – A USB kill cord for laptops

#251

Post by matheusmoreira » Wed, Dec 15, 2021, 6:45 PM UTC

maltfield wrote: post #189

LinuxBender wrote: post #40

There are mentions in this thread about false positives, risk of data loss, others. This made me think of Star Trek's use of a self destruct phrase. Obviously their method is too slow, but you could have a "duress" phrase and a "all clear" phrase. User-Defined Phrase: "Please dont kill me", activates "duress" mode. - A daemon listens in the background for a phrase of your choice. When detected, your laptop makes a so…

BusKill does not ship with destructive triggers. The current app is limited to locking your screen. Future releases will include soft/hard shutdown. We do have a "LUKS Header Shredder" trigger (which we call self-destruct as it renders all the data on the FDE disk useless), but we (intentionally) don't include it by default and raise the barrier of entry because of the risk of data loss. We'll be publishing a more de…

Does it support destroying keys in hardware tokens? Would be nice if plugging my yubikey into a specific USB port automatically destroyed all keys inside it.

Re: BusKill – A USB kill cord for laptops

#252

Post by tjader » Wed, Dec 15, 2021, 6:49 PM UTC

DarylZero wrote: post #248

tjader wrote: post #183

Earlier quoted context omitted.

Of course not, but then you're saying USB is a security flaw. My point is that given how universal USB as long as a device can do both input and output it's going to be very hard to stop some exfiltration from being possible. Do you really think a bug report should be filed on all OS's for allowing USB drives and keyboards to be plugged on a running system?

I was saying that the existence of the non-implementation of USB proves the possibility of access controls on USB. Convoluted way to put it I guess. For some reason was intuitive to me (proof of existence by example, more trivial example better). Having access controls on USB-HID is just a local policy choice where most people would choose convenience over security.

I agree, and it makes sense for some security oriented OS.

But the comment I replied to seemed to suggest that the possibility of data exfiltration via USB is a bug in any OS.

Re: BusKill – A USB kill cord for laptops

#253

Post by multjoy » Wed, Dec 15, 2021, 6:50 PM UTC

dane-pgp wrote: post #210

djweis wrote: post #140

Earlier quoted context omitted.

That's referred to as rubber hose cryptography.

That's also why Assange (and others) developed the Rubberhose file system[0]. It's based on the game theoretic idea that if your adversary has no way of knowing how many hidden partitions you have, then you have no way of proving to them that you've given them all your secrets. As such, there is no benefit to you revealing any secrets under torture, because the torture would continue even after you've told them every…

A state liable to torture you may simply kill you instead. Or torture you and kill you, even if it serves no particular purpose.

If you're in the business of protecting your secrets against torture then you need to also be protecting them against death because that is grimly inevitable.

Re: BusKill – A USB kill cord for laptops

#254

Post by matheusmoreira » Wed, Dec 15, 2021, 6:50 PM UTC

eloisius wrote: post #97

lmilcin wrote: post #94

Earlier quoted context omitted.

The problem is, if they are serious and suspect you might be prepared and technical savvy, they will never allow you to operate the device.

Yep. Pretty much all nerd solutions to physical or legal threats are genius but also worse than useless. Here's a $5 hammer, hit him with it until he gives us what we're looking for, so goes the comic I saw once.

This is effective against legal threats. I remember at least one case in my country where one person was saved by truecrypt. They even asked the FBI for help on decrypting it.

Hopefully civilization is not so far gone that police will imprison, torture or kill for failing to incriminate themselves. If it gets to the point cold-blooded torture is on the table, you'll probably get killed anyway.

Re: BusKill – A USB kill cord for laptops

#255

Post by matheusmoreira » Wed, Dec 15, 2021, 7:04 PM UTC

kingcharles wrote: post #160

yholio wrote: post #77

Good to have if you run a dark net marketplace or a political disident ring from public libraries. An additional refinement is to autolock the device if a certain personal key combo (ex. Shit - vol up - vol down) is not pressed every few minutes in response to an audible click. If not unlocked in a minute or so with a complex password, the device halts to a disk encrypted state and unpowered ram, minimizing the windo…

Exactly. You need something not for when your laptop is removed from you , but when you are removed from your laptop. Also, if you are being targeted this hard you need to have something for when you are left in front of your laptop and a gun is put to your head. Or the attackers threaten the welfare of your family.

If someome is pointing a gun at you, it's probably too late to do anything. There should probably be cameras and motion detectors monitoring the perimeter in order to provide early warning.

Re: BusKill – A USB kill cord for laptops

#256

Post by tbabej » Wed, Dec 15, 2021, 7:08 PM UTC

captaincrunch wrote: post #157

tbabej wrote: post #7

For the Yubikey owners out there, a while back I wrote a blog post on how to achieve a similar setup using a Yubikey [1]. All it requires is a lanyard to attach the yubikey to. [1]: https://tbabej.com/Yubikey-secure-session-setup/

Anyone needing a Yubikey would be very lucky to see them just hanging out of a computer, would just a bonus for the evil actor to also ruin your day and pull it out.

The way I've implemented this is that the yubikey is on an extensible lanyard which is almost always around my neck. So while an evil actor could definitely unplug it to ruin my day, stealing it would be a tad bit more difficult :)

In any case, the primary idea here was not to prevent stealing the laptop, but to prevent walking away from the laptop without locking it.

Re: BusKill – A USB kill cord for laptops

#257

Post by kingcharles » Wed, Dec 15, 2021, 7:12 PM UTC

matheusmoreira wrote: post #255

kingcharles wrote: post #160

Earlier quoted context omitted.

Exactly. You need something not for when your laptop is removed from you , but when you are removed from your laptop. Also, if you are being targeted this hard you need to have something for when you are left in front of your laptop and a gun is put to your head. Or the attackers threaten the welfare of your family.

If someome is pointing a gun at you, it's probably too late to do anything. There should probably be cameras and motion detectors monitoring the perimeter in order to provide early warning.

The second part is harder to defend against. I didn't flinch when LEO pointed a loaded gun at me and threatened to shoot me, but as soon as they threatened my wife I told them I would sign whatever fiction they wanted to write, which I did. It just took me close to 8 years of being in jail to get a judge to look at it and tell them off and throw out the document.

Re: BusKill – A USB kill cord for laptops

#258

Post by matheusmoreira » Wed, Dec 15, 2021, 7:13 PM UTC

WesolyKubeczek wrote: post #141

Say I'm an investigative journalist, gathering information about some bad guy embezzling all politicians that matter in a small country and doing all kinds of criminal stuff, including murders. I'm careful. I'm using a laptop that has this kill switch. I only keep my work on this laptop, it's so sensitive. The bad guy gets a whiff I'm digging around him. He sends armed thugs to my lair. They enter, so I pop the kill…

If they send assassins to your home because you know too much, OPSEC no longer matters. You're as good as dead if you don't immediately escalate to deadly force. Instead of destroying data, the computer should be uploading and publishing as much of it as possible so that whatever you're doing can't be stopped no matter what happens to you.

Re: BusKill – A USB kill cord for laptops

#259

Post by matheusmoreira » Wed, Dec 15, 2021, 7:16 PM UTC

comeonseriously wrote: post #84

Windows: Sorry, Dave, we can't shut your system down right now, you have 3 apps keeping it from shutting down and we have 37 updates to Edge Browser to install... Have a nice day.

Why would anyone serious about this be running Windows in the first place? A live Linux operating system is so much better. Tails is designed for this.

Re: BusKill – A USB kill cord for laptops

#260

Post by matheusmoreira » Wed, Dec 15, 2021, 7:26 PM UTC

Ensorceled wrote: post #26

marvin wrote: post #9

Earlier quoted context omitted.

How would a more violent arrest have solved anything?

The kill switch is useless if the accused is incapacitated before they could trigger it. No knock raids, which are inherently violent, to "preserve evidence" and reduce the risk to LEO happen about 20000 times a year in the US.

> No knock raids, which are inherently violent

> reduce the risk to LEO

I remember reading news about an american who killed an officer who entered without knocking. He was not convicted, it was ruled self-defense.