Re: [clueless] cryptography in DVD? Re: DVD-ROM problems

[Jens Axboe]

On Thu, Feb 10 2000, Pavel Machek wrote:
> > > Received Session Key:   B6 3D 2A 82 94
> > > not Authenticated
> > > Received Disc Key:      7A 7D 51 2E ED 2F 06 89 A6 6C
> > > Authenticated
> 
> Just out of curiosity, what is that? You need cryptography for your
> DVD to work? What is it good for? Why does linux need to know if drive
> knows some secret numbers?

It's just a (pretty stupid) authentication sequence. Some DVD's
contain encrypted blocks that the drive will refuse to read, if it
has not been authenticated. Not all DVD's are encrypted though.

And let me just add that the kernel doesn't contain any of the
crypto stuff, it just provides the hooks and acts as a blissfully
ignorant messenger :)

-- 
*  Jens Axboe <[e-mail]>
*  Linux CD-ROM Maintainer
*  http://www.kernel.dk