I’m talking about this article that I remember reading last year, but I never fully comprehend it. https://archive.md/qgBWB
Especially one of the images:
What does “BFU Extractions” mean? Does it just straight up bypass any lockscreen, even Before First Unlock?
The first time I came across that article, I just assumed if you have a strong password, your fine, now I’m not so sure, I’m starting to get a bit paranoid… 😖
It’s derived by both a key from the TEE and the PIN/password.
The reason for that is so you need both the user’s correct password, and the TEE to agree to hand out the key, which it may refuse to do if there’s been too many attempts. When you factory reset it just generates a new key, instantly making all the previous data permanently inaccessible. The TEE will also wipe the key if you unlock the bootloader or try to break in the wrong way.
It’s still only roadblocks though, extract the key from the TEE and you have unlimited attempts on what are usually weak 4-6 digit PINs. It’s not a lot of tries. Then you better hope you had a good password.