Encryption
The most common questions I am asked pertain to encryption. It is a huge part of the PS4's security which prevents us from analysing firmware updates, games, saves and more.
The reason I didn't mention encryption in my last article is because trying to defeat it would be a complete waste of time. The PS4 uses
AES (like the
PS3 and PS Vita), which is the same type of encryption used by the U.S. government.
People also don't seem to realise that there are multiple encryption keys used within the PS4; even if we found a way to decrypt save data, we still wouldn't be able to decrypt PUP updates for example.
With the current level of access we have to the PS4 there is no way to get any keys: brute forcing them would take longer than the lifetime of the universe even under ideal conditions, and I doubt any of the few engineers at Sony trusted with them would want to lose their job by leaking them.
The only exception to this is would be for implementation mistakes such as the PS3's infamous use of the constant 4 instead of what should have been a random number.
Whilst it is unlikely that Sony has made another mistake like this in the core of the PS4's encryption, it is not uncommon for other companies to accidentally give us access to unencrypted content. If you snoop around various games' update servers, you might find some debug ELFs for example.
Furthermore, encryption on the PS4 is handled by a separate processor, called SAMU, which is very locked down. Even with a kernel exploit, the SAMU processor is one of the few areas which we don't have complete control over. Although we can interact with it to decrypt almost everything, it is impossible to extract any keys so that decryption could be done externally.