There’s a budding format war in the movie industry, over which video medium will replace the DVD. The candidates are called HD-DVD and Blu-Ray. For some reason, HD-DVD advocates are claiming that their format can better resist unauthorized copying.
As far as I can tell, there is essentially zero evidence to support this claim. In fact, as James Grimmelmann neatly argues, there is really no reason to think that either of these technologies will be effective at stopping peer-to-peer sharing. Here’s James:
Already I’m confused. What will changing the physical format of non-interactive discs do to “stem rampant piracy?” The new format will have to be readable by some class of devices. It will have to be writable by some other class of devices. The level of “rampant piracy” of DVDs has never been a function of the weakness of CSS; the level of rampant piracy of HD-DVDs won’t be a function of the weakness or strength of the encryption algorithm.
Making HD-DVDs harder to copy than DVDs would take one of three things:
- It’s not practical to get at the bits except to throw them immediately up on the screen. But this would mean no HD-DVD readers or writers for computers – and the equipment vendors have been saying that HD-DVD drives for computers are one of their major markets.
- The discs (or disc substitutes) are in some way “smart” and do a two-way handshake with the computer so that you can’t, as with CSS, extract a key once and use it forever. But that would raise the manufacturing costs immensely, which defeats one of the major design goals.
- The discs are individuated and the readers have to check in with home base to be authorized to read a particular disc and get its particular key. But this would require every HD-DVD device to have an Internet connection.
Actually, they would probably have to do all three of these things, and more, to make any dent in P2P copying. The system will be attacked at its weakest point. If they fix only one or two of their many problems, the remaining one(s) will still be fatal.
Reporters and industry analysts are still surprisingly gullible about DRM vendors’ claims. What we have here is essentially a replay of the early security claims about DVDs, which turned out to be spectacularly wrong.
Perhaps people are drawing the wrong lesson from the failure of DVDs to prevent copying. It’s true that the CSS encryption system used on DVDs turned out to be laughably weak. But, as James notes, that wasn’t even the biggest problem in the DVD anti-copying strategy. Indeed, if you replaced CSS with an utterly unbreakable encryption system, DVDs would still have been easy to copy, by capturing the data after it was decrypted, or by reverse-engineering a player to learn the secret decryption key.
Here’s a good rule of thumb for reporters and analysts: If somebody claims to have solved a security problem that nobody has ever solved in practice before, don’t believe them unless they present independently verified evidence to support their claim.
