Inspired by this excellent writeup of the dangers of DRM I blogged this internally.
Digial Rights Management (DRM) is a security measure designed to prevent unauthorised use of digital content (usually music or video, but it can be applied to anything including a common old text file). The technology works by locking the file through some method of encryption. This means that only a player, e.g. Microsoft’s Media Player or Apple’s iTunes, that understands the locking mechanism will be able to open the file and play it. The player software or hardware, e.g. iPod, has been designed to only allow the unlocked file to be played, it will not make a copy of the file in the unlocked state – in this way the content remains protected.
At first glance this seems entirely sensible. Lock the file and only unlock to play it and don’t allow anything else to be done with the file whilst it is unlocked. However, the problem is that the only way this model can work is if only the maker of the player software knows how the locking mechanism works. Otherwise, anyone could create a player that unlocks the file, but then allows saving of unlocked copies. This is why, if you purchase a song on iTunes, you can’t play it on Windows Media Player and visa versa. There is also no way that you can disinvest in iTunes/iPod and keep your songs, you loose them all!
In other words, DRM means vendor lock-in. If you choose a DRM technology you will be locked in to that vendor and all the protected content that you purchase will be unusable should you try to change vendor.
I didn’t complicate matters by talking about how Open Source doesn’t offer a solution, nor get into the suggestion that as consumers we ought to be rejecting this technology. (The audience for my internal blog is senior management, and the blog should be giving them information that will effect decisions they have to make over the next 6 months.)