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Comment by Overtonwindow | Hacker News Reader

This raises an interesting idea: why not create two passwords for encrypted drives, one password decrypt the drive, another password completely wipes the drive. This way if someone is forced to give a password to decrypt something, that password renders the data moot.

Thoughts?

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Here's mine: destruction of evidence is a crime.

Probably not the best idea.

Hiding the partition or otherwise making the encrypted data hidden is probably your only bet.

Which would you rather go down for: destruction of evidence, or what's in your hard drive? I'm asking a technical question, not a legal one. There are many instances where this would be preferable than giving up the data.

If someone released such a tool, the feds would make sure to clone your hard drive before supplying the password to it, or write a patched version of the tool that reads it to remove the disk wiping call.

And then you'd be in really hot water.

An interesting talk on disk antiforensics: https://www.youtube.com/watch?v=qZtkANvDxZA

Of course, having watched this, the feds might look for such tricks...

I expect cloning to already be standard forensic procedure, but perhaps I'm wrong. If not, it should be.

yep. Work on the copy, or the copy of the copy in my case. It's digital with a hash, not a vhs tape

Ah cloning, very good point. So that raises a new question: Is there any way to prevent decryption of a drive, when the password is forcibly obtained?

That's why you say "There is nothing on that drive! Here you can have the password."

An actual forensics investigator will not work on a single copy of any data -- they'll make a bit-for-bit image of the hard drive in question and just work with an image.

I've thought of this but it usually takes some time to overwrite a lot of data. I'm not savvy enough to know if there's a way to nuke the data that quickly, other than non-software methods.

A friend of mine used to keep a massive electromagnet in is PC tower, that would theoretically wipe the hard drives when switched on. We never tried it. (He wasn't dealing in CP, just pirating mass quantities of movies and music).

FDE best practices are to encrypt the entire drive with a random key, and encrypt that random key with a derived key (key-encrypting key, or KEK) based on password. You don't have to nuke the whole drive; just the sector with the KEK-encrypted drive key.

Thanks, that helps me understand.

I think a better idea would be have it change the password/wipe data in the event that you do not log in within X amount of time (Think Lost). Keep your mouth shut for X time and there is nothing you can do to help them.

Speaking out my ass (IANAL) this is a deadman meant to protect against any attacker not necessarily law enforcement, this might be enough to keep you away from destruction of evidence charges.

You would need something more sophisticated that produced innocuous, but believable, data when given the distress key. Still criminal though.

Or easier to implement, something that accepts the distress key, says it is starting to decrypt, then spews tons of fatal checksum errors, "corrupted block", and so forth.

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