Re: hacksdmi?

[Ben Galehouse <bgalehou () PACBELL NET>]

"Granquist, Lamont" wrote:

> I think the idea is that they tag the content that you download off of a
> website with a watermark, then they run it through some kind of
> encryption/compression algorithm to the SDMI format.  The client that you
> use to download this is the same client that you use for playback.  The
> watermark is tagged with a specific key which will only allow you to play
> it back on the client that you used to download it.  Therefore, if you
> give the SDMI-encoded file to your friend they will not be able to play it
> on their player since it has a different key.  This is similar to your #1,
> but the goal is to watermark so it can be played in *only one* SDMI
> player, thereby to prevent sharing by 90% of the people out there.

They'll never get rid of alternative file formats and players.  The only
reason to make a watermark that survives file format conversion is to
assume that such conversion will happen.

If they are depending on lack of alternative players, they don't need
watermarking, they need tamper resistant hardware-only playback
devices.  DeCSS, but done with a technical clue.  Which is to say
expensive to do right, and difficult to maintain - look up the history
of skipjack.  Bascially, if everybody insists on using their own
computer, life is difficult.  Maybe if you figured out how afford to
hand out tamper resistant cards like cue-cats...

I don't think that it what their motive is. But maybe they have such
hubris. I have seen a computer book technology which claims to somehow
prevent the installation of debuggers.  Never underestimate corporate
hubris.