You aren't legally required to unlock your door and let the police in with a warrant. They will force their way in without your consent however, in some cases with out asking nicely first.
To which law enforcement will say: "but there is no analogous way to force our way into strong encryption, so we need to create one." To reiterate: I think that would be bad. Backdoors are bad.
Given the choice, I'd rather have warrants compelling people to unlock, than a law saying that encryption has to have a backdoor so law enforcement can force their way in.
On the other hand, if you can be compelled to divulge the passphrase to any encrypted container, what happens if you forget it? What happens if you happen to have a block of random-looking data? It might be an encrypted container -- or it might be something entirely different.
If I were to go through my old hard drives, USBsticks and whatnot, I'm reasonably sure I'd stumble on to random blocks of data and/or encrypted archives with passwords long since forgotten. If I could be punished for not producing matching passphrases, those could become a huge liability, very quickly.
Plus, it would be an easy way to incriminate. Drop an encrypted usb in the belongings of the person, and use that as an excuse for putting them in jail. Hell, it would be a lot more convenient than the War On Drugs.
This is a very interesting thread. I didn't think I'd ever feel differently about this issue, but you've really made me consider some other implications of locking police out of phones. Thanks for chiming in.
