Live data from Hacker News

BusKill: A kill cord for your laptop

tech.michaelaltfield.net

221–230 of 272 posts

Re: BusKill: A kill cord for your laptop

#221
post #186
post #171

Earlier quoted context omitted.

Better opsec would have saved him some grief as well. Before even touching on his habitual use of coffee shops near his residence to run the Silk Road... > The connection was made by linking the username "altoid", used during Silk Road's early days to announce the website, and a forum post in which Ulbricht, posting under the nickname "altoid", asked for programming help and gave his email address, which contained hi…

He would still have gone to prison no matter what (the government can make up evidence), but they may not have been able to seize his Bitcoin without stealing his laptop.

Does that matter with a double life sentence.

Re: BusKill: A kill cord for your laptop

#222

I will sometimes go to the university library to do some work and I'm always amazed at people who will go to the restroom or something and leave their laptop sitting there without a lock or even logged out. I always use a kensington lock and lock my screen whenever I have to leave my laptop. If I had a macbook I would be taking it with me. I know the locks won't stop someone who really wants to steal it but with so m…

What do you attach the other end of the kensington lock to?

The desk?

Re: BusKill: A kill cord for your laptop

#223
post #196

Earlier quoted context omitted.

That'll be a lonely hill to die on. We in California collectively decided that theft under $950 is not a big deal and should be fought less vigorously: https://en.wikipedia.org/wiki/2014_California_Proposition_47

That was a mistake. Criminals now very purposely run off with just shy of $950. Theft is way up in California. Meanwhile, in Texas you'd just shoot the laptop thief, either as soon as aware of the imminent theft or as the thief flees. It's fully supported by the law: https://lawofselfdefense.com/statute/texas-sec-9-42-deadly-f... Law enforcement in many communities would congratulate you for a job well done.

Controversial opinion maybe, but I personally don't think anyone deserves to lose their life for stealing a laptop.

Re: BusKill: A kill cord for your laptop

#225

Earlier quoted context omitted.

Assuming the laptop is still online / comes back online to receive the wipe command...

... and you are conscious and have your hands free :)

Or still be in possession of your phone, if eysomeone is trying to gain access to the data on your laptop, good chance they will be interested in your phone too

Re: BusKill: A kill cord for your laptop

#226
post #186

Earlier quoted context omitted.

He would still have gone to prison no matter what (the government can make up evidence), but they may not have been able to seize his Bitcoin without stealing his laptop.

Does that matter with a double life sentence.

No clue how prison works? Do watch a few documentaries. Money's important inside.

Re: BusKill: A kill cord for your laptop

#227
post #169

Earlier quoted context omitted.

If your attack vector is adversaries ready to deep freeze your laptop, perhaps you should do your computing in a more secure location :)

A secure location is an ICBMable location. (Not that anyone realistically has this problem, but “so safe that Bin Laden would still be alive” feels like the right level of overengineering when it comes to OPSEC.)

> Not that anyone realistically has this problem,

Drone strikes hit and kill hundreds of targets each year. Some on as little intelligence as an IP address used to click a link in a tweet.

Re: BusKill: A kill cord for your laptop

#229

Earlier quoted context omitted.

In theory an adversary could deep-freeze the computer the moment the kill cord activates. Sufficiently cold RAM doesn't loose data immediately when it loses power, allowing the adversary to make a copy and read the decryption keys from RAM. Though if this is part of your threat model you should be much more concerned about a thousand more mundane problems, like adversaries reconstructing keystrokes from keyboard vibr…

I would expect the unmount of an encrypted filesystem to secure delete the encryption key from memory. My understanding of the memory freezing attacks is that you don't unmount it, you just kill the power by removing the battery. With this method, you would still be able to freeze the RAM, reboot the computer, dump the RAM, and disassemble the kernel memory, and discover where the disk encryption key was stored: in t…

My preferred method is a custom kernel build that does a few extra obfuscation steps before or after encryption on each data block. While you might find my key in ram, good luck decompiling my kernel module based on a bitrotted ramdump. Simply not storing the key contiguously unless there is an actual IO operation going in is a good start - scatter it around the heap so a simple search won't find it.

Re: BusKill: A kill cord for your laptop

#230
post #196

Earlier quoted context omitted.

That was a mistake. Criminals now very purposely run off with just shy of $950. Theft is way up in California. Meanwhile, in Texas you'd just shoot the laptop thief, either as soon as aware of the imminent theft or as the thief flees. It's fully supported by the law: https://lawofselfdefense.com/statute/texas-sec-9-42-deadly-f... Law enforcement in many communities would congratulate you for a job well done.

Controversial opinion maybe, but I personally don't think anyone deserves to lose their life for stealing a laptop.

I don't think that's controversial, I think most of the world shared that opinion.
Post reply on HN