[Gigachad]

Even if you could find the original crypto header, You still need to know the password to unlock it. On iphones, the secure enclave will hold the decrypted key while its running but you need to enter the password after a reboot.

[Gigachad]

Also if someone had the technical capability to do this. I would be infinitely more concerned about them having an exploit which allows them to hack my next phone and grab all the data while its running.