Destroying an Encryption Key = Destroying Evidence?

Factual Questions
1

I am intrigued by the currently legal battle/question over whether one can be compelled to give up an encryption key to decrypt documents that might incriminate oneself.

My understanding is that the basis of the argument for compelling decryption is by analogy to, say, a safe. They’re not asking you to testify against yourself, they’re just asking for you to open the safe. But what if you can’t open the safe?

Some people have claimed to have forgotten the password. The problem there is that, if the judge doesn’t believe you, you just get held in contempt of court for an arbitrary length of time. No good.

So, here’s the hypothetical: Worried about some documents that may be incriminating, but also worried about being held in contempt, some guy encrypts them, then destroys the encryption key.

I believe he’d be guilty of obstruction of justice. Is he guilty of anything else? Not sure if this should go in IMHO or GD, but I think/hope there’s a legal precedent for this sort of thing.

2

In your example, the situation is the same as if he were to just delete the documents, or shred them. He would be accused of destroying evidence, obstruction of justice, whatever. Destroying documents by encrypting them and then intentionally discarding the key is no different from any other method of doing so. They would still have to prove intent, but “I encrypted them right after I got the subpoena and then lost the key, whoopsie!” is a pretty lame story.

Now, if he had been using encryption for years and then just happened to “lose” the key when the shit hit the fan, that might be more credible. Unlike cases involving “forgotten” passwords, it is a lot easier to prove you don’t have something than to prove you don’t remember something. The police can get a warrant, search your house and office, and if they don’t find it, who’s to say it isnt really lost? The timing of your “loss” would still be dubious, but maybe a good lawyer could get you off.

3

If the encryption is good enough to defy cracking without the key, how is that different from simply destroying the original documents?

4

In particular, for any worthwhile encryption algorithm, you can probably make a good case that it is more difficult to decrypt without the key than in would be to reconstruct a printout of the document from the output of a shredder mixed in with a dumpster of unrelated documents. So a good case could be made that encrypting and destroying the key would be illegal wherever shredding a document would be.

5

The case hinged around the question of where the state’s rights to subpoena material in a court case ends and fifth amendment rights against self-incrimination begin.

A better analogy is a combination lock vs. a key lock. The police can show you the warrant and ask for the key. Can they show you a warrant and demand you tell them the combination or you unlock it for them? How is making you reveal a combination or encription password different than compelling you to admit where you were last Saturday during the murder, or put you on the stand without your consent and demand you say where the gun is?

The discussions I read said that if it comes from out of your mind, it’s fifth protected. If it’s physical actual, “I can do it without your inpu” data, then it’s subject to a warrant.

your OP is moderately ambiguous. Do you mean you have a file of garble - pretty much impossible to memorize - that can unlcok the encrypted documents? Whatever medium that file is on, if you erare it, you are destroying evidence. Depending on the evidence, you may be better off with the obstruction-of-justice charge than with the evidence out in the open. Case law around electronic material is still evolving, but essentially if you detroyed the only real way to read a bunch of electronic documents, I would imagine the argument could be made the documents are effectively destroyed. (If you encased the documents inc oncrete adn dropped them in the ocean, they could dredge for a few years, eventually find them, and maybe crack open the concrete and read them - but for the practical purposes of the trial, you disposed of them.)

Once you realize that the material of any sort would be evidence and you destroy it, you are obstructing justice. (Maybe a lawyer can clarify the issues here). For example, Martha Stewart IIRC got a call warning ehr the feds were investigating her tipster for insider trading. She then deleted the log entry on her computer about her stock ip phone call. Even though she re-typed the entry a little bit later, she was still convicted of obstruction for the deletion.

The twist in the Colorado case was that they had a awiretap of the woman cleverly telling her husband that the incriminating documents were in the encrypted folder; so the state’s argument was that they were not requiring the woman to incriminate herself because they already knew these were incriminating documents, they were just ordering her to produce what she had.

Note the other distinction… the police cannot go fishing. They need to say exactly what they are after, then only look for that. If they are looking for a gun, they cannot open letters and file folders (unless they are bulky and fat and could be hiding a gun). Similarly, if they are looking for stlen VCR’s they can’t read your files (unless the warrant includes “and corrspondence about disposing of stolen VCR’s”, say.) Anything found which is not in plain sight or obvious during search for legitimate search targets, is off limits.

The difficulty is that if you refuse to open a combination lock the police can call in the torches and jackhammers and get there in a day or less. (IIRC you are not obliged the materially assist them). SO, the incentive is to either have an intact house or not, for the rest the outcome is the same. With electronic documents, it will take the jackhammers several lifetimes of the universe.

So the question is - is a password or combination testimony or physical evidence?
If you can forget it, IMHO it’s testimony.

In Colorado, they bypassed the question when the hubby produced the password.

6

There is a difference in the key to a safe vs encryption. In the key or even combination to a safe example the safe could be opened by force, so for all intents and purposes the safe is open it’s just a matter of method. So the handing over the key is just a formality.

In the case of a encryption key the decryption is not a done deal and from what I know of it it would be unlikely that they would gain access without the key.

7

What if the password itself contains incriminating evidence? What if my password was I_Am_D.B._Cooper!

Further, though this may be getting away from the thread a bit, what if there is evidence of a wholly unrelated crime in the folder stored in such a way that it will fall under the ‘plain view’ exception. So the police have a very specific warrant for invoices related to stolen VCRs, but in the same folder I have an image of myself standing behind the grassy knoll. Even if they wouldn’t be able to open a .jpg per the terms of the warrant, the thumbnail preview would show its contents, the filename would be descriptive, etc.

8

That’s the question, right?

If I had a safe that was really hard to crack, and I lost the key, I can hand the safe over in response to a warrant and say “do your best”. I clearly haven’t destroyed the contents of the safe, I’ve just made them inaccessible.

9

It wasn’t stated in the OP, but one potential difference is that the encryption could be done ahead of time, and the key destroyed later.

If you want to go a bit further, there are cryptographic protocols that would allow for additional complications. For example there are key sharing schemes where a key can be split into n pieces, such than any m pieces are sufficient to recover the key, but less than m makes it impossible. You could split a key with 7 friends, and make it so that any 5 of them can decrypt. So, ordinarily, any 2 of them can lose or destroy their keys without preventing recovery. If 3 do that, decryption is impossible. But which of the 3 friends is at fault in that case?