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PAM Duress – Alternate passwords for panic situations

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Re: PAM Duress – Alternate passwords for panic situations

#161
post #105

Earlier quoted context omitted.

"You could even spawn a process to remove the pam_duress module so the threat actor won't be able to see if the duress module was available" This scenario was considered by the author

Technically you'd also need to rewrite the logs in a plausible manner (removing the mentions of the PAM module and potentially replacing it with their "normal" equivalents) and depending on your threat model, actually securely erase the files so that disk recovery software can't later restore the deleted files.

If your threat model is someone that will even invest the time to sift through your logs, it might be wise to disable (persistent) logging in the first place.

Re: PAM Duress – Alternate passwords for panic situations

#162
post #87

Comments are full of gunpoint scenarios, but I think a far more likely scenario for most HN readers is law enforcement / customs agents asking you to unlock your device during travel or some other random checkpoint so they can scan it. In that case, I doubt the officer would even have a clue about the use of a duress password to selectively and silently delete some private data. I think the biggest risk would be that…

On linux distros, at least before wayland, it was easy to make your account hidden from the gdm chooser (e.g. by putting it in a different group).

Then you could setup a dummy account that doesn't have too much of interest in it.

Combined with pam crypto to encrypt your home on login, the result is something that is reasonably private against casual inspection.

I used to use this back when I couldn't afford to travel with a disposable use laptop...

Re: PAM Duress – Alternate passwords for panic situations

#163
post #146

Earlier quoted context omitted.

Despite rumors to the contrary, the police aren’t stupid. They are trained to ask questions in ways that elicit a confession or falsehood. The simplest example is asking “Do you know why I pulled you over?”. Typically, people spontaneously confess to speeding, sometimes they break down and admit that someone is wrapped up in a rug in the trunk. The courts have consistently ruled that customs is different and you can…

Time to post this again: https://www.youtube.com/watch?v=d-7o9xYp7eE (Don't talk to the police)

Customs is different in two crucial points:

1. The probability of your being in a stressful situation without the option to leave is high - you probably arrived via plane, so you can't simply go back, and you don't know the local laws well.

2. You usually know that a customs checkpoint is upcoming.

So, in that case, it's far better to prepare (i.e. don't bring things you don't want searched/compromised) and cooperate.

Re: PAM Duress – Alternate passwords for panic situations

#164
post #35

Earlier quoted context omitted.

As long as the sides are the employee's choice (i.e. the threat actor needs to not be able to know which eye is the duress one).

And you'd want to hide the eye choosing/scanning process so nobody could just watch an employee to figure out their preference.

Scanner is something you look in with both eyes. And then while your eyes are completely hidden you close one eye.

Heck. You could set it up so that it scans both eyes and then does a second scan where you choose what your ok signal is (both eyes, right only, left only, no eyes).

Re: PAM Duress – Alternate passwords for panic situations

#165

Earlier quoted context omitted.

It’s silly nerd porn. The “real” problem is either: (a) You know the authorities want access to your data because , and you travel across a border with it. (b) You possess sensitive information and are not aware of law enforcement’s desire to get it; (c) You’re swept up at random; (d) You’re a criminal, or carry a paper trail of potential illegal activity. Solutions: (a) Means you are stupid. The only way to win is n…

(e) You are a whistleblower who doesn't want to be dragged off to a military prison and tortured

Which is the same as (a). Either have an USB stick with plausibly-deniable encryption or, better yet, store the data somewhere online (in encrypted form, of course) and download it once you crossed the border. There is no reason to have it readily available on your laptop.

Re: PAM Duress – Alternate passwords for panic situations

#166

Earlier quoted context omitted.

So you're saying if I'm held at gunpoint or forced to surrender my password at the US airport that a password to clear my account of anything would be useless? Neither of them know anything about me. It reminds me of the Trezor hardware wallet that allows you to have multiple passwords into your account. If your forced to give access you can log into the version with little in it. Nobody knows that you have secondary…

Without knowing what your captor already knows about your device, deleting data they may expect to find is a pretty high risk gambit.

If you think that them finding your data is the better option, you can always revert to using your normal login credentials.

Re: PAM Duress – Alternate passwords for panic situations

#167
post #23

What I never quite understand is how this can work in practice. When someone is under real duress, they do not always behave in a logical way and may be too stressed to remember certain details like a password that they never use...

You don’t understand how someone can remember a password under stress?

If you used that password twice two years ago when you installed the module and you're suddenly pulled in an interrogation room in a foreign country? When you have about one chance to enter it right while some very angry officers look over your shoulder?

I can absolutely see that.

Re: PAM Duress – Alternate passwords for panic situations

#168

Earlier quoted context omitted.

And with a little bit more force they beat the password out of me anyway regardless which system I use...

If you are so easily swayed, you would probably not be in an adversarial situation with a government anyway. But this article is about a system for giving up passwords under duress without necessarily compromising all your security, such that your antagonist has no way of knowing or showing that there's another password concealing more important information.

https://xkcd.com/538/

Re: PAM Duress – Alternate passwords for panic situations

#169
post #146

Earlier quoted context omitted.

Time to post this again: https://www.youtube.com/watch?v=d-7o9xYp7eE (Don't talk to the police)

Customs is different in two crucial points: 1. The probability of your being in a stressful situation without the option to leave is high - you probably arrived via plane, so you can't simply go back, and you don't know the local laws well. 2. You usually know that a customs checkpoint is upcoming. So, in that case, it's far better to prepare (i.e. don't bring things you don't want searched/compromised) and cooperate…

[deleted]

Re: PAM Duress – Alternate passwords for panic situations

#170

Training is very important in duress systems. I once worked in a place with a keypad duress code on the security system. If you prefixed your security PIN with NN-, it was the duress version of the code and would trigger a silent alarm. This was setup long-ago, and not communicated. One night, the keypad was acting glitchy. Partially out of frustration (countdown is running), and partially to test, I ended up acciden…

I had a similar false trigger trying to make an international call from our office phones. I didn’t know the exact incantation of the prefix, but knew it was 9 for an outside line and at home I used 011 then the country code. That didn’t seem to work, so I thought maybe I needed to drop the zero, resulting in me inadvertently dialing 911 and hanging up when that didn’t give me the dial tone I expected. I found the ri…

I always find it crazy when systems make you dial 9 for an outside line, for this very reason.

Did the same thing myself my first week in college. Got the police. Told them what I did and I could hear the eye-roll on the other end of the line, and was told I was the third person that day.

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