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Author Topic: Xbox Signed Code  (Read 67 times)

Cheerio

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Xbox Signed Code
« on: March 06, 2003, 05:40:00 AM »
nope....its error codes written onto game disks, that make it hate anything unsigned.......me thinks...
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BenJeremy

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Xbox Signed Code
« Reply #1 on: March 06, 2003, 06:06:00 AM »
QUOTE (mxx117 @ Mar 6 2003, 09:38 AM)
Ok, i just thought this up, but if the Xbox verfication loop (aka the black chip) runs everytime that a cd is placed in the drive, and the Xbox can run Audio CD's, then there must be some line of code or something ID'ing the disc as Audio.  Now, if we could figure out what this is, then we could merely place this code as a lead-in to any homebrew games/apps that we need to.  Any ideas?

maxx

Wrong logic.

The BIOS controls the signing process (which is why modchips replace the BIOS with a patched version).

Each application has a signature, created using a private key, creating a signature that can be CONFIRMED using a public key (contained in the BIOS). If you tamper with the program, the signature changes, and the BIOS will reject it. The thing with Xbox games is that the XBE includes a media byte describing where the application can be run from (as well as a region code); when you change that, you change the signature, and since the BIOS will also reject running a program from an area not allowed by the media byte, most games have this byte set to ONLY DVD-ROM. DVD-R is also a recognized type, as is any recordable media.

In other words, if you tweak the app in ANY WAY, even just to nudge one byte to tell the Xbox it can run from a non-DVD-ROM disk, it changes the signature, which will get it rejected anyway.

This has NOTHING to do with the way audio abnd DVD movie discs are run, only with applications.

Since we do not have the private key used to CREATE the signatures, we cannot run any software we create on an unmodded box, PERIOD.
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Videogamebuyer14

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Xbox Signed Code
« Reply #2 on: March 09, 2003, 05:27:00 PM »
I heard something like this a while ago, like when the first chips were invented and px let out their releases, but anyways, it said to burn the .iso as an audio disc, and it would be bootable, cause the xbox bios, would think it was an audio disc.

This is purely fictional, and this will not happen. Unless the bit code is found, there is no future for this option.
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