Xbox 360 'modding'

One or two people who know I'm a hardcore gamer have asked me about the new 360 'mod' and if I am considering getting it done, some even believe it is the first step in getting home brew and other such niceness running on the console.

Well no, I don't intend to carry out this modification, legal and ethical issues aside if you think this mod is a good idea you probably don't understand how the security on the 360 actually works and what has and has not been broken. I will try to explain.

When Microsoft designed the 360, they decided to allow for certain programs to run from DVD recordable. This was probably to allow stores to quickly and easily duplicate demo or promotional disks. In order to accommodate this, an Xbox 360 executable file has several flags or markers embedded into it, that tell the 360 if it can load the file based on what sort of media it is on.

The mod that the pirate community is currently distributing works by getting the 360's DVD drive to lie about what kind of disk you put in it, basically it tells the machine that the disk is actually a factory pressed disk and not one you just bought down the market and recorded.

Now, here comes the technical part. All the 360's software is protected with a digital signature. This is basically an encrypted 'fingerprint' of the file. If you change the file then the fingerprint no longer matches. This is why nobody has produced their own software and put it on DVD-R and managed to load it into the 360. Since the fingerprint is encrypted, you cannot simply change the fingerprint based on what you have done to the file. In fact you cannot change this fingerprint unless you are in possession of the key that originally created it and only Microsoft is likely to have that and they aren't going to be sharing it any time soon. This isn't some sort of voodoo, it based on tried and tested encryption techniques that are used all over in business and the Internet, generally by paranoid geeky people who like to pretend someone might actually go to the trouble of intercepting their e-mails :)

So, obviously this means no home brew, but what else does it mean? Well, you are likely to get banned from Xbox live if you use this mod, if not now then certainly at some point in the near future. Since Xbox live is pretty much the best part of many X360 titles and also a lot of fun to use just to keep in contact with your gaming mates, its a bit of a large chunk of functionality to sacrifice. Furthermore, even staying off Xbox live isn't likely to do you much good in the future. Future titles are likely to require an update to the 360's BIOS before they will run(much like the PSP titles do now) It is a pretty safe bet that these updates will check for such things as this mod, and prevent the game booting. Many believe that the hackers will simply hack new titles that do this and remove the firmware check, but of course thats not actually possible because of the digital signing. Remember that changing even one bit of a file will mean that the digital signature won't match and thus the game will no longer boot.

So, to sum up, this mod will let you play pirate copies of the current crop of games and possibly a few in the near future, and only off line. So unless you are happy with the current selection of games and don't use Xbox live (including Xbox live arcade) this really is a waste of time.