Using Watermarks to Combat Piracy

TheEvilOverlord writes to tell us PC Advisor is reporting that researchers at the Fraunhofer Integrated Publication and Information Systems Institute have developed a new watermarking system to help track and combat piracy. From the article: "The system lets content providers, such as music studios, embed a watermark in their downloadable MP3 files. Watermark technology makes slight changes to data in sound and image files. For instance, the change could be a higher volume intensity in a tiny part of a song or a brighter colour in a minuscule part of a picture. Even the best-trained human eyes and ears, according to Kip, can't detect the change."

Comments

Human?

[biocute]

Even the best-trained human eyes and ears, according to Kip, can't detect the change.

Who says anything about using human senses to detect the watermark? If these watermarks are embedded by machine, I'm sure it won't be long until Watermark Bob creates a "cleanser" program to detect anything unusual, and maybe even remove it.

Re:Human?

[Iphtashu Fitz]

I'm sure it won't be long until Watermark Bob creates a "cleanser" program to detect anything unusual, and maybe even remove it.

Good point. All you'd really need is two or more copies of a given file, each with their own watermarks. Do a relatively straightfoward binary diff on the files and you'd quickly spot the watermarks. Normalize the diffs based on the similarities between the multiple file copies, and voila! Instant un-watermarked file.

Re:Human?

[sabernet]

Instant defense: Sony's rootkit allowed a hacker to hijack my PC and steal my files;)

Re:Human?

[Kadin2048]

The intended use of watermarking, at least as I see it, is less for mass-released files than for prerelease or limited-release uses.

E.g., radio stations get copies of songs weeks before the CDs actually hit stores -- and suspiciously, the songs tend to show up on P2P networks soon after they go out to radio stations. What the music producers would really like to be able to do is trace the leaked files back to whoever put them on the internet, and then get medeival on them for breach of contract.

You can imagine similar uses for prerelease screenings of movies that go out to critics, film review boards, etc. It's less about preventing piracy than it is about finding the snitch afterwards so they can be made an example of. Really, the piracy deterrent is not technological (the watermark), but social (whatever punishment gets inflicted). The watermark is just facilitating the latter.

I suppose in theory if you had a watermark that could be embedded into the file quickly and easily, you could use it on downloaded music (like the iTMS) to see if people were sharing files that they purchased, but really I think systems like this are designed to catch big fish, not Joe Preteen who's ripping files that he bought off of Napster and putting them onto Kazaa.

A lot of similar systems are used with images; actually many of the techniques used for watermarking are used for steganography (it's arguable that watermarking is really a form of steganography), like Least Significant Bit padding for one. There are also systems that have a robust enough watermark that they will survive printing and scanning, although they tend to begin to mess up the image slightly.

Defeating?

[Anonymous Coward]

...and in order to defeat such a wonderful scheme, all you have to do is re-watermark the image/music/video.

I've yet to see a scheme that reliably survived that test unless it was specifically designed just for that test (like embedding high power signal in several random places), and upon detection, looking for that signal in those random places (hope is that 2nd watermarking didn't wipe out -some- signal data).

In any case, Watermarking doesn't work! Even Microsoft's researchers said so (damn, can't find link).

Short memories -- this was called SDMI

[Thagg]

This was rolled out years ago, and plotzed with a mighty thud when it happened, due in no small part to the http://www.cs.princeton.edu/sip/sdmi/faq.html">wor k of Felten and his grad students at Princeton.

Basically, the Powers That Be came up with a very good watermarking system, but even the best system can be defeated by a very determined adversary -- especially since the watermarks can't be updated once the CDs are shipped.

Another problem that I've always had with these systems is the proof issue. If the RIAA tries to prosecute you for having watermarked files, they have to demonstrate the watermark. I can't imagine how they could show that without revealing exactly how the watermark is detected -- and once they do that, you should be off to the races.

Anyway -- this has been tried, and it has failed. The SDMI system was really quite sophisticated, and it failed almost immediately.

Thad Beier

Re:Short memories -- this was called SDMI

[Fnord666]

Another problem that I've always had with these systems is the proof issue. If the RIAA tries to prosecute you for having watermarked files, they have to demonstrate the watermark. I can't imagine how they could show that without revealing exactly how the watermark is detected -- and once they do that, you should be off to the races.

This is exactly what "zero knowledge" proofs are supposed to be able to do. Using such a protocol allows me to prove to anyone interested that I know something without revealing what that something is. the proof does not impart any new knowledge to the person/entity that is receiving it about the information. In this context it would mean that the RIAA would be able to prove that the files had been watermarked using their private mark and were thus their copyrighted material without revealing any information about how that watermarking was done. The proof would not rely on revealing the method. Graph isomorphism is a commonly used example.

I don't know if anyone has incorporated a practical application of this into any sort of watermarking scheme, but it could be used for this purpose.

Re:Why should Clear Channel care about file sharer

[sam_handelman]

I respectfully disagree.

  Your problem is that you are accepting the recording industry's propaganda, i.e. "We oppose piracy because people will listen to pirated copies instead of buying CDs."

  The *real* objection of the recording industry, and this goes double for clear-channel, is that P2P sidesteps their promotion monopolies and makes the music market harder to manage and control. Fragmentation of the market costs them their niche at the top of the foodchain.

  The best example of this attitude was, a while back, movie industry executives noticed that some heavily promoted presumed-blockbuster (I forget which movie it was, The Island maybe) was getting far less than the guaranteed level of attendance given the advertising budget. Careful marketing research traced this phenomenon back to bad word of mouth, which was spreading faster than it had in the past, chiefly by cellphone.

  The response of the movie industry was NOT "gee, we'd better stop making movies that even brain damaged 11 year-olds regard as intellectually insulting", but instead "is there any way we can make it illegal to badmouth our movies by text message? Libel law, maybe?" Fortunately, they concluded that was a non-starter.

  That long tangent aside, look at clearchannel. Clearchannel's business model depends COMPLETELY on the willingness of the general public to agree-to-like whatever 30 songs they decide they want to play/promote in a single month. They also need to make sure that people keep listening to the radio and not to ipods. Alternate routes of distribution are just as much a threat to clearchannel as they are to the recording industry.