limits of watermarking (Re: First Steganographic Image in the Wild)

Ben Laurie ben at algroup.co.uk
Wed Oct 17 05:23:03 EDT 2001


Adam Back wrote:
> In my opinion copymarks are evil and doomed to fail technically.
> There always need to be playble non-certified content, and current
> generation watermarks seem easy to remove; and even if some really
> good job of spread spectrum encoding were done, someone would reverse
> engineer the players to extract the location parameters and then they
> too would be removable -- and in the end even if someone did manage to
> design a robust watermarking scheme respecting Kerchoff's principle,
> the identity information is weakly authenticated, and subject to
> identity theft or the content itself could be stolen or plausibly
> deniably claimed to have been stolen and this only has to happen once
> for each work.

The thing that gets me about all this is that exactly the same argument
can be made for all existing media - and, although piracy is rife,
no-one is attempting to mark videotapes or CDs, AFAIK. So why all the
fuss about more modern digital media? Has no-one noticed all the ripped
videotapes, CDs and DVDs? Are we really expected to believe the whole
media reproduction industry is ever going to switch over to producing
each disc individually, expensively watermarked? So what's the real
agenda?

And don't tell me its because broadband will eliminate physical media:

a) I believe physical media will always have higher bandwidth than
broadband - why? Because you have to feed the broadband from somewhere,
and archive it somewhere.

b) Even if physical media goes away, individual watermarking blows away
multicast - and broadband will just never work without that.

It seems to me that putting the details of the purchaser in plaintext on
the beginning of the file and making it illegal to remove it is as good
a protection as you are ever going to get - but that would ruin a whole
bunch of business plans, so I guess no "expert" is going to admit that.

In short, the agenda, it seems to me, is the business plans of companies
in the watermarking business. No more, no less. I'm amazed the media
moguls are willing to waste so much of their time and money on it.

Cheers,

Ben.

--
http://www.apache-ssl.org/ben.html

"There is no limit to what a man can do or how far he can go if he
doesn't mind who gets the credit." - Robert Woodruff



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