This. In the U.S. at least, the 5th amendment gives you the right not to incriminate yourself. A search warrant doesn't change that.

Not all authentication methods are equal it appears. Fingerprint, facial recognition, other bio-metrics aren't considered the same as if you need to "speak" your password to someone. In other words, they can make you scan your finger or look into a camera, but they can't force you to tell them your password.

Yes, there is a distinction in US law between acquiring physical and "mental" evidence.

The former can be forced (e.g. I must provide my safe key) and the latter cannot (e.g. I don't have to reveal my password).

The line gets blurry: keyed lock vs combination lock, password vs SSH key.

> (e.g. I must provide my safe key)

Surely you don't need to participate in the activity? They are just allowed to take and use it, I assume?

In the US, you are required to assist in the execution of a warrant (though naturally officers prefer executing it without your participation if possible).

You must unlock your door, and you must unlock your safe, if it is within the scope of the warrant.

https://www.quora.com/Can-a-search-warrant-compel-me-to-unlo...

To be fair, AFAIK, this is only the case in criminal proceedings. In civil proceedings, your failure to comply will be held against you.

How about forcing you to type the password, behind a Mantle of Power if need be, such that they can decrypt the disk, without ever knowing the password?

The way the law works here in the USA is that anything that requires you to disclose the contents of your mind (a passphrase, an explanation of where you were, your name) cannot be compelled because the fifth amendment precludes the use of that information to convict you.

Things that you ARE (such as fingerprints, DNA, hair color, photo, sample) can be compelled by a court order (e.g. a warrant) because they aren't the contents of your mind but physical aspects of your existence.

That's why the use of a strong passphrase that isn't tied to a biometric is important if you're worried about this sort of thing.

Can't the police/a warrant compel you to open a combination safe? That would be a case of you disclosing a passphrase/something in your mind, but contrary to your assertion.

Nope.

They can certainly open the safe. They just can't compel you to TESTIFY to something.

The contents of your mind are sacrosanct. If they can compel you to divulge a combination, then they can also discern that you had access to that safe by virtue of possession of the combination. Not allowed by our laws.

As I understand it, in the US at least this is indeed the line. Same goes for combination vs keyed locks: you can't be forced to self-incriminate by sharing information, but you can be held in contempt for withholding evidence.

I imagine it gets murky around things like SSH keys, which are technically a kind of password, but too big for a human to remember - and therefore must be "instantiated" in a physical device somewhere.

> I imagine it gets murky around things like SSH keys, which are technically a kind of password, but too big for a human to remember - and therefore must be "instantiated" in a physical device somewhere.

A likely interpretation might be: an SSH key without a keyphrase is like a physical key, and you must hand it over, while a key with a keyphrase is like a combination lock, where you must hand it over but you are not required to state the keyphrase.

Simple password that you can remember encrypting your SSH key, know they can't compel you to give the password unlocking the key.

On the other hand, not giving your password right away may be interpreted as an indication that you have something to hide (which you inevitably do), and they may tag you for even further scrutiny.

Also, UK: don't give your password, go to prison. Indefinitely.

What about plausible deniability keys? 1 password hides the real stuff, and the second one that you give to the police just gives them access to your porn collection (which someone very well might want to hide!).

Well, they don't matter wrt. the law. Either the prosecution is convinced you gave up all the keys (you win), or they believe you gave them a key that was just a distraction and they throw you in jail unless you give them the other key (you lose).

How do you prove yourself innocent then? You did give them the keys.

The point is that you look exactly the same as an innocent person.

You are taking the only possible pathway to being proved innocent.

It'd be like if I were to say "It doesn't matter what you do. The police are corrupt anyway, and will take you out back and shoot you no matter what. Guilty or innocent, if you get accused of a crime, you are dead."

And if they are going to lock you up no matter what, then you may as well use multiple plausible deniability keys. As you said, it doesn't matter what you do, the outcome stays the same.

> How do you prove yourself innocent then? You did give them the keys.

Well, prosecution needs to have a legally convincing argument that indicates it is likely you have another encrypted partition you're not giving up keys to.

In fact, the situation is no different from this: say you're a murder suspect and a neighbour saw you carrying several large heavy sacks into your car and you drove away. Say what really happened is that you went and buried some bags of toxic waste in some location, and then went and buried a dead body in another location. When asked by prosecution, you confess to burying toxic waste and tell them where. The rest of the outcome of the trial depends entirely on whether you've successfully convinced them that you just buried the toxic waste.

That's fine, but your argument is effectively that you are screwed no matter what.

If you are truly innocent, the prosecution might claim "oh they have extra keys that they haven't given up", and there is nothing you can do to prove them wrong.

Like jbg said in another comment here, the legal system doesn't work that way, where the prosecution can claim you did stuff and you have to disprove the claim. The burden of proof is on the prosecution.

So you are agreeing with me that this tactic of plausible deniability with multiple encryption keys works then?

Which is it? Does encryption allow you to hide from the law, or can innocent people just be proclaimed that they are hiding something and that they have to give up keys that don't exist?

It is one or the other, because encryption plus multiple keys makes you 'indistinguishable' from an innocent person who truly cannot give you a key that doesn't exist.

You're proposing a false dichotomy.

The tactic might work, but how well it would work would depend on what other evidence was presented that you do have another encrypted area. For example, if they analyse the partition you gave them the key to and show that it hasn't been booted in 18 months; they cross-reference the cached DHCP leases with the times you were known to have been online using that machine and find discrepancies; they might even have secretly imaged your disk a month earlier and show that a large amount of supposedly free space has changed content in the meantime.

(Maybe they even have you recorded telling someone that you have a second encrypted area on the machine.)

If there's no such evidence, then it ought to be pretty hard to convict you.

In most jurisdictions, the prosecution being _convinced_ that you are guilty isn't enough to throw you in jail -- there's still the small issue of proving their case in front of a judge.

Thanks for pointing this out. I was thinking "judge or jury" but wrote "prosecution" in my comment above.

Which is terrifying, as the whole point of plausibly deniable passwords is that attitude will end up with innocent people in jail for data that doesn't exist have.

Until it's tested in court on a gray area case, it's hard to know for sure, but I'm pretty confident that UK courts would apply the "reasonable doubt" criterion to the fact that the defendant indeed posesses an encrypted volume they have not provided the keys to.

I.e. if the defendant can reasonably claim that there are no further encrypted volumes on their device, I don't believe they would be imprisoned under this rule.

This is one of the major issues with laws requiring password disclosure.

First of all, a truly careful criminal can use this method to comply with the law while still hiding what they are really after -- negating the usefulness to some extent.

Secondly, once law enforcement catches on to this, they can then claim that someone that does disclose a password actually gave them a plausible deniability or duress key, and they haven't actually given up the real key, and thus the innocent person could potentially be convicted for not giving up a password that doesn't even exist.

Indefinitely? So if the police digs up an old encrypted disc from your attic, and you legitimately forgot the password, you can be put away for the rest of your life?

Is there currently someone in UK prison for not giving up their password?

Only one case which I've seen mention of: http://www.bbc.co.uk/news/uk-25745989

He got an additional four months for the failure to disclose the passphrase, on top of five years three months for Terrorism Act offences.

The Register reported a man getting 13 months (http://www.theregister.co.uk/2009/11/24/ripa_jfl?page=1) - though I couldn't find a better reference.

BBC also reported on a teenager getting 16 weeks (http://www.bbc.co.uk/news/uk-england-11479831).

In both cases it seems they were jailed purely for failure to disclose passwords and not in conjunction with any other offence.

Please stop spreading FUD about RIPA, there is no "indefinitely" involved, the maximum sentence is two years, unless it relates to child indecency, in which case the maximum sentence is increased to five years. [1]

[1] https://en.wikipedia.org/wiki/Key_disclosure_law#United_King...

I've heard the judge can then ask you again, and you can go back to jail if you refuse, because that's a separate offense or something.

Do you have a written citation for that, something from Out-Law.com (or equivalent), or from a qualified solicitor or barrister, which backs up the "I've heard..." up a little?

Not trying to be a hard ass, but I don't think HN benefits from people spreading "legal facts" (c.f. indefinite imprisonment) with an authoritative written tone but without citing legal precedent, or a detailed analysis of the statute in question.

I'm not a lawyer but I imagine if you were taken in front of the same Magistrate's Court or Crown Court, refused to decrypt the _same_ data a second time, were convicted under RIPA, sentenced, you'd have a damn good argument at appeal and it would very likely be quashed. IANAL.

To put more substance behind this opinion, we can look at the Sentencing Council, which when drawing up sentencing guidance, frequently uses the term "fair and proportionate" [1] which is something of a cornerstone remark about how the judiciary should go about dealing with infractions of the law. Reasonable humans would say going to prison twice for the same thing is neither fair, nor proportionate.

[1] https://www.sentencingcouncil.org.uk/news/item/new-sentencin...

I have no substantial evidence to speak of. And I thank you for knocking me off my horse, I was being hasty. Have my upvotes.

Now I checked Wikipedia about those laws, it appears France (my country) has a similar law since 2001. Bummer, I guess.

> Also, UK: don't give your password, go to prison. Indefinitely.

Identifinitely? I think even for terrorist charges you can only be held for so long?