[smiley1437]

> You actually don't have to power it down. If you hold the power and volume buttons for 2 seconds and reach the "slide to power off" screen, the phone is already hard locked. You then always have to enter the passcode to unlock it.

Iphones have 2 states when it comes to encryption:

Before First Unlock (BFU) - everything is encrypted. The most difficult state to hack.

After First Unlock (AFU) - data isn’t fully encrypted. Maybe it's for performance reasons. In this state exploits exist which police can use to get data.

Your suggestion of getting to the 'slide to power off' screen does NOT hardlock the phone (it does not put it in BFU).

It just means it requires a passcode. However, since it is in AFU mode, data can be exfiltrated with the right tools.

You should definitely power it down to be secure.