Here's the thing though; you can do that, and it'll protect your data, but any nation can still prevent your entry for exactly that reason.

"Oh, you brought an empty phone? Give me access to your cloud account. No? Ok, you're never entering our country. Bye."

Ultimately yeah, they can refuse you for any reason they want and they don't have to tell you why. You're not a citizen, you don't have a right to enter.

Obviously you'd seed it with some fake data...

lulz, you should assume the NSA has access to anything you store in the "cloud".

Of course, but they already have it, and aren't impeding my travel. The Candian Border Control guys don't, and can.

> (...) but they already have it, and aren't impeding my travel.

But don't be mistaken, that based on the Snowden revelations, "they" may not have already had it, and needed another country's intelligence agency to access it first -- for them to get to whatever it might be, and possibly even use it against you, legally.

The Five Eyes may actually have it - so even if border guys don't, the Canadians may have access.

Okay but I encrypt locally first?

For that you would need to be able to fully trust your cloud storage provider, the ISPs used in transint to and from, the used encryption methods and last but not least: the baseband firmware of your phone.

It's highly unlikely that the Canada Border Services Agency, of all organizations, is able to defeat competent modern crypto implementations.

It's also quite unlikely that they can circumvent a basic `tar -c /dev/block/* | gpg -se ...` scheme that's trivially doable on unlockable Android phones. (Replacing the bootloader with a maliciously crafted variant that returns false partition data after bootup would work, but once again: CBSA.)

You're probably safe if you just do an iCloud backup and wipe followed later by a restore.

Certainly do replace the SIM card as soon as possible though, IMO. Unless you can verify it somehow.

If you are asked to provide your password, encryption will not help you.

Perhaps still better than trusting border patrol with physical access to the device.

No, if you trust the encryption (which implies the firmware), you don't need to trust the ISP or storage provider. That's the whole point of encrypting stuff.

Interestingly, in the case of handing over your phone, there are some odd quirks in security that make things a little topsy turvy. Normally, while the iphone has better device security, in the case where you are conceivably worried about firmware hacks (to the degree you think it's possible), the iphone presents as a juicier target, as the hardware is far more homologous.