A stupid question and it's probably already been asked here but...
if I use this method to backup a game, wouldn't I have to have a hacked firmware to play the game on my 360?
QUOTE(http://www.xbox-scene.com/xbox1data/sep/EEukZpklFAhkcWwSgZ.php)
As you (should) know, all Xbox 360 executables (XEX files) are signed by Microsoft (with a private key only MS has). This means that if you try to change anything to the XEX file, the signature will be wrong and the file will not boot.
Now ... to protect from booting an exact copy of a game from a DVD-R or other recordable media, microsoft gave each XEX file a 'mediaflag'. This mediaflag tells the Xbox 360 from which media (cd-r, dvd-r, dvd+r, dvd-rw, hdd, dvdxbox, dvdxbox360, ...) the XEX is allowed to boot. Changing this mediaflag in the XEX header is not an option as it'll break the signature of the file (see above), so ... what's done in this firmware hack is 'break' the detection of the disc.
Retail games usually get a mediaflag where they only allow 'dvdxbox360' (Xbox 360 discs - different than a normal DVD because it has some specific bad sectors and special info in lead-in/out that can't be written with a standard dvd burner). The modified firmware will trick the DVD drive into reporting a DVD-R (or other) as a DVDXBOX360 to the Xbox 360.