Overkill. Cross borders clean. I reset my phone every time I cross any border. And then resync everything I need on the other side. I have a TrueCrypt volume I download to my travel laptop. It's small but contains what I need when abroad.
The US has outlawed encryption in the past, and tools they once touted as promoting democratic freedom in oppressive regimes are suddenly seen as evil, so you'd probably need to remove all signs of TrueCrypt on your laptop as well.
Sorry, but I fail to see how an app locking you out is more overkill than wiping all of your devices every time you cross a border.
Depends on what you mean by overkill. Effort? Then yes. Security? Then no. If the data is there but inaccessible you can be detained until it is. If the data isn't there to begin with, there's no reason to detain you.
I'd call that more of an effectiveness thing than overkill. And it would be possible for an app to not unlock the phone until it enters a certain geofence, like the hotel.
That wouldn't work in the UK, where not providing plain text when asked carries a prison sentence.
The app wouldn't accept a password, just a time and location to unlock. I'm not sure if that's better, but it technically sidesteps that issue.
I said plain text, not password. And it doesn't side-step anything because when you're in front of a judge and explain why you cannot provide plain text, they'll take your phone from you, get it to the location you tell them, and if none of that yields plain text, you go to jail. Two years, they give you for that.
Who has gotten two years for that and lost the appeals?
If they were actually on you, they would find the hidden volume too.
Sorry, my post was a bit sparse on detail. I keep a TC volume (file) on three separate public file shares. My laptop is clean. I download and install TruCrypt, and download the TC volume once I'm through customs. When I say clean, I mean that there's no trace of anything on any of my devices while I cross a border. That means there's no TrueCrypt, and no TrueCrypt volume on my laptop at all. Why should there be? We have the Internet.
Of course, after they have your personal details, they'll now do an Internet search and find this post. You just gave them your game plan ;)
Indeed I did. But how would anyone prove that this scenario isn't just hypothetical?