OK, test it on "Petit Copter (Japan).iso"
1) xbox_dernd.exe - derandomizer
like "nasos deux", it doesn't change the structure of the file, just replaces "random data block" with block full of "JUNK", it is like zeroing but it serves as a mark
you will get a file called "Petit Copter (Japan).f401863e.iso"
f401863e is a seed for the random generator
2) xboxRegen.exe - regenerator of random data
replaces blocks full of "JUNK" with random data blocks, generated by using seed number
xbox_dernd is tweaked to be compatible with the Petit Copter for test purpose
the tweak is, that it bruteforces only 1/16 part of full range
from 0xf0000000 to 0xffffffff (f401863e)
to speed up the test process, it tooks about 8 seconds on my rig
brutforcing the full range will took about 8 minutes
P.S. 7zipped iso is 48,7 Mb