each game has its own key
each country version has its own key

each *revision* uses the same key.

different xors are required even for different revisions for each because the xors are one big giant hack. this means that if raz gets rid of the board for a game/country then no more xors can be produced for that until he gets another and the game won't run. this is *not* how things should be with the correct decryption keys.

the Sega work in Mame has been done properly, if we find multiple games using the same encrypted cpu part (we just found some more smgp revisions) then they will work fine without any additional data being required.

As for doing things properly making it too easy to bootleg the new games, I'm still not convinced. If CPS2 encryption is half as good as the Sega encryption then you can't guess the keys (8k!) without being able to dump decrypted data from the boards, and if you can do that you can bootleg them anyway.

hacked xors can be created because the majority of the data is *probably* the same and because the xor method is just a giant hack.

as for scam, i'll let you draw your own conclusions, no comment.



> That would still be some progress in my opinion :) Up untill now Raz has had us
> believe that each game or revision has an entirely different encryption key.
>
> > > Thats exactly what I was thinking. There would be no point in making an xor
> > to
> > > run previously xored program roms run in a different region. But on the
> other
> > > hand, I'd imagine some knowledge of the encryption is needed to run unxored
> > > program roms with a hacked xor. It would be nice if someone in the know
> would
> > > comment with a little more than just "nope".
> >
> > Calling it a hacked XOR could mean anything even just a change to the rom
> > checksum. Which would probably be required.
> >
> > Understanding the encryption wouldn't be required just knowing how the xor's
> are
> > applied to make changes to code.
> >
> > >
> > >
> > > >
> > > > This line makes me think other wise.
> > > >
> > > > "these new XOR's contain incorrect information in relation to what the
> real
> > > > encryption would return for many addresses when compared to real
> hardware."
> > > >
> > > > If they were just changing code to alter the region it wouldn't affect the
> > > game.
> > > > Other than the normal problems of using region codes with some games. I
> > think
> > > > what he's getting at is some clone games may use the same encryption key.
> > And
> > > > since the code would be similar too the XOR works. But different revs. or
> > > > regions will still have code changes that would be incorrect when you
> apply
> > an
> > > > XOR not made for it.
> > > >
> > > > If this is true it leads me to speculate that the key could be quite small
> > if
> > > > there's a lot of games that work like this. The remaining games could be
> > brute
> > > > forced easily if the algorithm was known.
> > > >
> > > > Consider this why would someone bother hacking XOR's to do a region switch
> > > when
> > > > most CPS2 emu's support region switching. And why would Raz comment on
> > > something
> > > > that pathetic? Really no one would care.
> > > >
> > >
> >
>


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