What part of the XBox game is signed?

[SCVirus]

I am wondering the reason why you cannot simply make a 1:1 backup of an xbox disc using either, An Xbox with linux on it, and simply ripping the disc like you would any disc on a computer, or use a modded pc dvd-rom drive to rip the game from your pc? I though you couldn't use backups because 'they arn't signed' in which case why can you not copy it 1:1 and copy the 'signing' with it. This has been bothering me whats the reason this can't be done? Have i got something completely wrong about the mechanics of this system?

[AXmichigan]

its just like the dreamcast
the pc cd/dvd drives just cant read em
only xbox can read the xbox discs (originals)

[SCVirus]

thats not what i asked, please reread my post. the only thing i said about a pc reading them is about the modded dvd-rom drives (with both hacked firmware and soldering) that can read xbox discs, but it has almost nothing to do with my question so if you need to ignore that part.

[Quall999]

He did, the disks are like DC disks. They are pressed and signed. You copy the files off the disk, not the signature. Just like when you copy a dc game. You copy the game files and not the other boot layer. You have to do more work and make it auto-boot (editing and creating files).

Like DC games, xbox games are multi burned (not just layered).

[Quall999]

Here is a little more direct answer about the matter.
http://forums.xbox-scene.com/index.p...c=288735&st=15
Basically, it find out how big the XBE is, what it was designed for, and what the XBE looks like.

It takes this information and encrypts it with the MS private key.
The Xbox takes it and decrypts it with the public key.

(RSA works by letting you encrypt with one special key, and then it can only be decrypted with the other special key. The public and private keys.)

If the information on how big the XBE is, what it was designed for, and what the file looks like is right it'll run. If not, error 21.

So simply swapping the sign code won't work.


To make it work you would need the private key, probably under heavy guard at the MS offices.

Each game must be signed by a 2048bit key. That is very large. Most things are only 128. MS's xbox key is a "raoaring pimp" compared to others. Anyways, developers send the final cut of the game to MS, and then have it signed. The developers don't even know the key. Basically, it is ms's way of saying "if you make a game, i want to approve it, then you must pay a royalty in order to have it ran on my xbox". It is the dual layered print that kills us.

This is as simple as I can put it. The xbox can only decrypt the key. Basically, the xbox can see if something can be run on the xbox, but not why it can be ran on the xbox. It is like a wall with someone talking behind it. You can hear everything they say, but you cannot see the person that is talking. You see, hacked pc firmware won't copy the key, because it can only decrypts it and cannot encrypt it (you need to know how it encrpts in order to generate the key on the disk). Modchips remove the check. You don't need a master key to do that.

learn more: http://www.xbox-linux.org/docs/projectboverview.html

[SCVirus]

thank you that link answered my question perfectly.