Pointer authentication (PA) is a mechanism to prevent the modification of pointers in memory using a cryptographic hash, or pointer authentication code (PAC). With the integrity of a pointer verified against the PAC, a crash is triggered if the values do not match.
First introduced by ARM in 2017 and adopted by Apple in 2018, pointer authentication basically requires the attacker to guess the PAC of a pointer after modification to prevent triggering a crash when modifying code in memory.
