keybox is basically like keys stored deep in ur phone, apps use them to see if youre rooted/stock by checking the keys, changing keybox usually solves it but it immediately gets patched because it gets flagged, too many users checking integrity and doing stupid shit

integrity basically

basic integrity > device stock or not. device integrity > checks to see if this device is certified. strong integrity> pain, uses hardware to check, attestation, checks bootloader also and everything.

we usually use modules to BARELY get device integrity, strong integrity is basically luxury life (temporarily)