According to his latest blog post, Hotz sees the reserved SPU with its precious cache of decryption keys as his primary target now. "Some people pointed out that I have not accessed the isolated SPEs," he wrote on his blog. "This is true. Although as far as doing anything with the system, it doesn't matter. The PPE can't read the isolated data, but it can kick the isolated SPEs out. Decrypt the PPE binary you need using the intact SPE and save the decrypted version. Kick out the SPE, and patch the decrypted version all you want."
In short he's looking to the use the processor core (the PPE) where he does have access to emulate the isolated SPU (for those interested, strictly speaking, the "SPE" is the name given to the group of all the SPUs). Holding him back - for now - is Hotz's contention that the PowerPC implementation of C++ is being used at this level, and it's somewhat removed from the ARM coding he is used to when hacking mobile devices like the iPhone.
It is safe to say however that Geohot's hack will open the door to piracy by offering low-level access to any one technically minded to do with as they will. Right now, he's looking to extract the crucial decryption keys from the isolated SPU and post them on his blog so others can, as he puts it, "join in the fun" without him having to reveal details of his actual hack - which by his own admission is far from complete or stable.
However, Sony's attempts to secure the game delivery system and the Blu-ray drive itself mean that there'd still be a huge reverse-engineering job required to enable piracy. While PS3 might well be hacked today on a low-level, further levels of protection remain in place to prevent copying games, and will require a significant effort in terms of reverse-engineering to overcome. Those expecting working PS3 games to appear on torrents in the next days or weeks are going to be disappointed.
PlayStation 3's security on the Blu-ray drive itself is (was?) pretty much untouchable and was designed to foil the kinds of attack seen on competing systems. Xbox 360 was compromised owing to the unencrypted nature of the firmware on the original DVD drives. Wii was hacked because the system itself was so similar to the GameCube that when the old hardware was cracked, the new revision fell with it. PlayStation 3 is far smarter. Not only is the drive software itself encrypted, but it's widely believed that the mandatory firmware updates can also reflash the Blu-ray drive too - even if the drive was hacked (it never has been) it would be re-secured next time you updated your PS3.
Completing the puzzle is the file system encryption on the disc itself. While PS3 game dumps are as old as the system itself, they are almost entirely useless and a complete waste of internet bandwidth for those that have been uploading and downloading them - the dumps do not contain the encryption keys apparently hidden in Blu-ray's proprietary ROMmark copy protection system, which remains inaccessible. While Geohot's hack potentially opens the door to piracy, in any eventuality games would still need to be heavily patched to operate without the encryption even on a compromised system.
Geohot himself won't be coding anything that directly attacks these systems, and reckons that his hacking blog isn't intended for those looking for user-friendly Jailbreak-style software like his various iPhone unlocking tools.
"If you are expecting some tool to be released from this blog like blackra1n, stop reading now," he posted. "If you have a Slim and are complaining this hack won't work for you, stop reading now. WE DO NOT CONDONE PIRACY, NOR WILL WE EVER. If you are looking for piracy, stop reading now. If you want to see the direction in which I will take this blog, read the early entries in the iPhone one. Information on this blog is for research purposes only."
This protects Hotz from legal action on the part of Sony and allows him to present the hack itself as the key to making PlayStation 3 an open platform. However, assuming the hack itself is published, and decryption keys posted, it's only a matter of time before someone else takes on the challenge of peeling back the remaining security, and the first downloadable, copied games hit PS3.