About 10 years ago, I read a paper that suggested mitigating a rubber hose attack by priming your sys admins with subconscious biases. I think this may have been it: www.usenix.org/system/files/…/sec12-final25.pdf
Essentially you turn your user to be an LLM for a nonsense language. You train them by having them read nonsense text. You then test them by giving them a sequence of text to complete and record how quickly and accurately they respond. Repeat until the accuracy is at an acceptable level.
Even if an attacker kidnaps the user and sends in a body double, with your user’s id, security key, and means of biometric identification, they will still not succeed. Your user cannot teach their doppelganger the pattern and if the attacker tries to get the user on a video call, the added lag of the user reading the prompt and dictating the response should introduce a detectable amount of lag.
The only remaining avenue the attacker has is, after dumping the body of the original user, kidnap the family of another user and force that user to carry out the attack. The paper does not bother to cover this scenario, since the mitigation is obvious: your user conditioning should include a second module teaching users to value the security of your corporate assets above the lives of their loved ones.
I am well aware of learning, but people tend to learn by comprehension and understanding. Completing phrases without understanding the language (or the concept of language) is the realm of LLM and Scrabble players.
“In 2015, despite not speaking French, Richards won the French World Scrabble Championships, after reportedly spending nine weeks studying the French dictionary. He won it again in 2018, and multiple duplicate titles from 2016.”
Smart. I like the idea of replacing biometrics with something that can’t easily be cloned - learned behaviour. Perhaps with a robust ML approach you could use analysis of gait, expressions, and other subtle behavioural tics rather than or in addition to facial/fingerprint/iris recognition. I suspect that would be very hard to fake - although perhaps vulnerable to, idk, having a bad day and acting “off”.
Having read the paper, there seems to be a glaring problem: Even though the user can’t tell an attacker the password, nothing is stopping them from demonstrating the password. It doesn’t matter if it’s an interactive sequence – the user is going to remember enough detail to describe the “prompts”.
A rubber hose and a little time will get enough information to make a “close enough” mock-up of the password entry interface the trusted user can use to reveal the password.
The private key, or a symmetric key would break the algorithm. It’s kind of the point that a person having those can read it. The public key is the one you can show people.
The purpose is to access the data. This is a bypass attack, rather than a mathematical one. It helps to remember that encryption is rarely used in the abstract. It is used as part of real world security.
There are actually methods to defend against it. The most effective is a “duress key”. This is the key you give up under duress. It will decrypt an alternative version of the file/drive, as well as potentially triggering additional safeguards. The key point is the attacker won’t know if they have the real files, and there is nothing of interest, or dummy ones.
An encryption scheme is only as strong as its weakest link. In academic terms, only the algorithm really matters. In the real world however, implementation is as important.
The human element is an element that has to be considered. Rubber hose cryptanalysis is a tongue and cheek way of acknowledging that. It also matters since some algorithms are better at assisting here. E.g. 1 time key Vs passwords.
Full disk (/partition) encryption means you don’t know what files there are until you decrypt. Additionally for that sort of encryption scenario you fill the partition with random data first so you can’t tell files from empty space (unless the attacker can watch the drive over time).
If you set it up correctly, this is essentially what it does. You have a disc that is, say, 1tb. It’s encrypted, so without a key, it’s just a bunch of random noise. 2 keys decrypt different vaults, but they each have access to the full space. The files with the proper key get revealed, but the rest just looks like noise still, no way to tell if it’s empty space or if it’s a bunch of files.
This does have an interesting effect. Since both drives share the same space, you can overfill one, and it’ll start overwriting data from the second. Say you have a 1tb drive, and 2 vaults with 400gb spent. If you then go try to write like, 300gb of data to one vault, it’ll allow you to do so, by overwriting 200gb of what the drive thinks is empty space, but is actually encrypted by another key.
It’s been a while since I’ve messed with this tech, and I’m mostly a layman, but this should be a fairly accurate depiction of what’s actually happening.
Game theory would lead you, as the tortured, to realize that they’re just going to beat you until death to extract any keys you may or may not have, so the proper answer is to give them 1 and no more. You’re dead anyway, may as well actually protect what you thought was worth protecting. Giving 1 key that opens a dummy vault may get the torturers to stop at you, thinking this lead is a dead one.
Probably best to avoid systems with known deniable encryption methods, and keep your dummy data there. Then hide your secrets e.g. in deleted space on a drive, in the cloud, or a well-hidden micro-sd card. All have risks, maybe it’s best of all to not keep your secrets with you, and make sure they can’t be associated with you.
There are some cases involving plausible deniability where game theory tells you should beat the person until dead even if they give up their keys, since there might be more.
I mean, I’d definitely do it to SBF if his crap wasn’t cleaned out already. Though admittedly I’d largely keep going just because this world DESPERATELY needs fewer SBF types in it…
I’ve used a duress password with crypto containers since the old TrueCrypt introduced me to it a while back. Sure you can have the password and unlock the vault but it’s just text file notes in there that aren’t at all important. In reality though, no one would ever give a shit about my data enough to even ask me my password.
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