When it comes to the PlayStation 4, what holds the main encryption to the console is a separate processor named SAMU. This stands for Secure Asset/Access Management Unit. This is a really tough processor to actually hack into, and it's the real reason why we aren't seeing crazy modifications happening to the console at the moment.

until someone handles SAMU, there won't be any online (spoofing, passphrase keys, index.dat spoofing, etc), since everything is there, and won't get out. There is a lot more stuff it has inside since of course, you can just imagine it as a factory. It runs and operates a massive amount of information in there! To simplify it, a few things to understand what's in there:

Contains:

Spoofing - Trick the system to allow you to go online with a modified console thinking it's running on an OFW (Official Firmware).

Passphrase Keys - Protects Private Information, and also controls operations in the PS4 that contain cryptographic systems. If we have the key, we can control this easily with patience.

Index.dat Spoofing - DevKit Debug Settings had a specific button combo to show more in-depth info about the console. That information pattern comes from index.dat.