Where do I read more about this - it sounds fantastic and yet I just assume "proprietary = lazily implemented and they can read my keys cos it's on their server"
There was a talk at passwords^10 (2010) about security of pins/keys in iphone/android/windows phone (IIRC). Don't recall who the speaker was, and all the links to talks/programs etc have gone to bitrot (might be possible to find on archive.org, I've yet to try that).
If I remember correctly an encrypted iphone (4 I guess?) was the most secure, but with a bit of hackery one could use the device itself to bruteforce the pin (and thus access the key, and then the data). Not sure if that's actually been patched in later iterations of the iphone.
If you find this stuff interesting, consider going to passwords^14 (August 5th-6th, Las Vegas): https://passwordscon.org/
If I remember correctly an encrypted iphone (4 I guess?) was the most secure, but with a bit of hackery one could use the device itself to bruteforce the pin (and thus access the key, and then the data). Not sure if that's actually been patched in later iterations of the iphone.
If you find this stuff interesting, consider going to passwords^14 (August 5th-6th, Las Vegas): https://passwordscon.org/