Where's Wil?

So having seen a lot of coverage of the HD-DVD hack over the past couple of days, especially re: the events on Digg, it's worth clearing up some misconceptions of exactly what it is, what it does, and how it's going to affect film watchers going forward. Many people have called it a hack to allow piracy, some have called it copy protection, some have said it's HD-DVD for Linux. I followed this stuff closely whilst covering it for bit-tech, so here's the deal.

HD-DVD uses a copy protection standard called AACS. The encryption uses two sets of keys - one key is on each HD-DVD disc, and is specific to that title. The other key is on the player (either software, like WinDVD, or hardware, like the Toshiba players). The first time AACS was cracked, a hacker called muslix64 found out how the title-specific keys were stored and how to access them, meaning that a database could be built up of each disc, allowing copying. Of course, this has the downside that you need to find the particular code for each disc you want to copy, and those codes could change between pressing runs.

The second time AACS was cracked, muslix64 went a step further and found out how the player key is stored and used. Since a player must be able to play every disc out there, this key is more 'universal' than the title-specific keys. The key was gotten from Intervideo WinDVD on the PC, a software player.

09 F9 is the WinDVD AACS code, and it will play every HD-DVD disc previously made. However, here's where things start changing. In accordance with the AACS revocation rules, the code has now been revoked, meaning that any new HD-DVD discs being shipped will recognise the 09 F9 code on any decription request and will refuse to allow playback. Additionally, Intervideo has had to push a mandatory update to WinDVD uses that changes the code and also stores it differently.

So what can 09 F9 be used for? Well, you can use it to build players that will play HD-DVDs made up until the revocation occurred, at the end of April. You can use it to build Linux software players, and to use ripping tools to make perfect, non-DRM copies of your HD-DVDs. You can't use it to rip DVDs pressed after the end of April.

But more to the point, 09 F9, aside from practicality, is a symbol - a symbol of the futility of DRM, of the consumer's annoyance at restrictions on fair use. It's a recognition that hackers will always, always defeat DRM. Whatever the code changes to, however Intervideo alters how its player-specific code is used, it will be, at most, a couple of months before AACS is broken again. And it can only be a limited amount of time before it's broken, permanently. Whilst you can revoke keys, you can't revoke the knowledge of how to find new ones.