I noticed the other day that when FIFA'09 for Xbox360 is patched with the latest update, the flags that specify what media the game is allowed to run from have changed. Originally it was allowed to boot from a standard original Xbox360 disc, however now it is only allowed to boot from a new media type which is basically an updated version of the original Xbox360 disc type.
Those who have ever looked into the depths of the Xbox360 disc authentication scheme know that a "new" type of disc authentication has been in the works since the Xbox360 was released. It is known as the AntiPiracy v2.5 checks, or AP2.5. Is this FIFA'09 patch a sign that AP2.5 is finally going to see the light of day? If so then the ban hammer is going to come down hard. Don't say I didn't warn you
The original Xbox360 game disc was reffered to as DVD-X(info)GD2, which I presume stands for Xbox Game Disc version 2 (with version 1 being the discs used on Xbox1). This new Xbox360 game disc just seems to be reffered to as an "updated DVD-XGD2″ , however to avoid confusion I will call this new disc type "DVD-XGD2.5″. Also since I am a lazy typer I will remove the "DVD-" prefix for the following text.
Based on what I remember from when I looked into the disc authentication, I can see three possibilities. In order of likeliness they are:
1) Possibly the XGD2.5 disc is actually physically the same as the XGD2 disc but has support for extra unknown challenge/response checks.
XGD2 discs are authenticated by a series of challenge response pairs. The Xbox360 sends challenges to the dvd-drive and then the drive sends back responses to these challenges based on information on the disc in the dvd drive. If the Xbox360 deems the responses to be correct, the disc is authenticated.
Current Xbox360 dvd-drive hacks work since the challenge/response pairs are stored in the security sector on the disc, meaning that all possible challenge/responses are known in advance. The best way for MS to solve this problem is to use challenge/response pairs that are not known in advance to the dvd-drive. So if a hacked dvd-drive receives an unknown challenge it will not have the correct repsonse to send back, therefore the authentication will fail and the copied game will not boot.
MS could do these extra checks when you connect to Xbox Live, and could even save unknown challenge/response pairs to a file on the flash of your Xbox360 in order to do the checks offline. They could also save challenge/responses to your flash when you update your console via Live or an update on a game disc.
2) Maybe the authentication of XGD2.5 is a superset of the XGD2 authentication. Therefore the FIFA'09 game could be pressed on the new XGD2.5 discs and still pass the XGD2 authentication checks. Then when MS is ready to initiate AP2.5 checks they could patch the game to only boot if it's disc passes the XGD2.5 authentication.
3) Or else I may just be wrong and there is no new disc type or it is totally seperate to AP2.5
lol!
