This isn’t a digital signature or anything like that. Instead, it’s increasing the size of pointers to include bounds and permission rights (R/W/X/etc), plus an

This isn’t a digital signature or anything like that. Instead, it’s increasing the size of pointers to include bounds and permission rights (R/W/X/etc), plus an extra tag stored somewhere else to prevent forgeries or mitigate corruption. So the only thing big corp gets out of this is software more resilient to memory corruption :-)