Free music or stealing?

Cox News Service ^ | 12-23-2002 | Phil Kleur

[VeritatisSplendor]

Of course, a REALLY sophisticated pirate could multiply the entire audio track by his own slowly varying factor of 0.99-1.01, but even here there are tricks to stop it. You put brief stretches where your waveform varies faster; those wiggles will stand out from the pirate's slowly varying wobble. If the pirate tries to use a rapidly varying waveform for the entire piece (it has to be the entire piece because he doesn't know where your checkpoints are, and by using an error-correcting code you can make sure he has to find nearly all of them), he will degrade the sound quality, and the segments where you vary slowly will be detectable because his wiggles will average out, so you can still recover your 4 bytes.

And that's just amplitude modulation, you can also do tiny amounts of frequency modulation which is even harder to distort (though your leeway might be a bit less than 1% if you want to avoid it being detectable to the trained musical ear).

The basic principle is simple -- you are hiding 4 bytes of information amidst 400,000,000 bytes of information. Steganography works in practice with much denser hidden info than that -- you just have to code it in a holistic way.

[VeritatisSplendor]

As I said in the reply following your reply (written before I'd seen what you wrote), you can do frequency modulation as well as amplitude modulation. And any idiot who makes the amplitude for the whole song constant will have an extremely inferior product.

Of course, a dedicated pirate can still record the song off the radio and copy that, and it will have a better dynamic range than your suggested method and be untraceable (the record company will be able to tell which radio show he taped it from, but that won't help them catch the guy). The point is not to make copying impossible, just to make HIGH-QUALITY copying SUFFICIENTLY difficult that people will buy the CDs instead, and this is certainly achievable.

[Bush2000]

Potential. And there's a problem. The file sharer denies sales, the armed robber steals merchandise off the shelf. The file sharer reduces theoretical sales, the armed robber in a very real way and empirically proveable way cuts into the sales of the store. But using your argument, white collar criminals like Ken Lay should be the primary target. No file sharer could ever cost any company what an SOB like Lay cost Enron. First thing's first unless you want to admit that you want the police to cater to your needs and enforce the law for your benefit first as opposed to going after the violators who do the most harm first.

When you exchange files, some nonzero percentage of people who would have bought the retail CD/disc/DVD will not do so. That isn't theoretical. It's fact. Consequently, the loss of sales hurts the record companies and the artists.

[Bush2000]

The same reason it wouldn't be wrong not to profit from other people's work.

You're walking in circles.

[Bush2000]

No file sharer could ever cost any company what an SOB like Lay cost Enron.

Moral relativism isn't going to make your case.

[general_re]

I think I still see a hole in it. Wanna put it to the test? ;)

[VeritatisSplendor]

What's the hole?

Remember, you have to destroy the watermark, which is designed to be just below the threshhold of aural detectibility (or just above it, but below the threshhold of artistic distinguishability), without degrading the sound quality, when you don't know exactly how the watermark is encoded. If you're thinking of "averaging" a whole bunch of different versions from different physical CDs, remember that you have both AM and FM encoding to deal with as well as other tricks like phase modulation between the right and left channels....good luck synching those up.

Theoretically, the fact that you are just trying to destroy the watermark rather than read it helps you, but I don't have to make your job impossible -- I just have to make it too much trouble compared to buying the CD or settling for a pulled-off-the-radio quality product.

[VeritatisSplendor]

A final mathematical point -- if I steganographically encode 400 bytes rather than 4, that means you would have to "average" more than 100 physical CDs to obscure the origin of the information -- otherwise I'll just be able to determine ALL the individual watermarks. This requires fancy error-correction, but information theory guarantees it's possible.

[RiVer19]

Does this mean that you'll have to register your CD purchase? And, they'll maintain a database of CD's and their owners???? Nuts man...just nuts....The cost of that PLUS the fact that it would turn off an enormous portion of the buying public.

[Jhoffa_]

They see the Internet as a large record store which they supply. They can't get it through their thick skulls that the Internet lets them sell their wares at a very low cost which lets them undercut Kazaa and Napster.

Well, I am sure it's only a matter of time before they come to their senses.

[Jhoffa_]

The record labels should have partnered with Napster and created a system where Napster on every search links users to a download page at the label where the searcher could buy the CD direct for say..... $6-$8 before s&h.

Again, why buy something you can steal for free?

BTW, I read that if it involves more than 10 works or a value of over $2500.00, it's a felony.

[Jhoffa_]

You would never cut it as an artist because your art would reek of being all about money and nothing more.

Don't be too sure about that, remember there's more to art than music and oil paintings.

Compare Britney Spears with A Perfect Circle and tell me who is the true artist.

I'll take Britney, just for the fondle factor.

[Jhoffa_]

Why get a woman to consent when you can rape her? Another perspective on the same "moral dillema."

Because rape is wrong, like stealing?