Tuesday, February 16, 2010

The state of Kindle backups and data portability, February 2010

I recently plugged my Kindle into my workstation's USB port for the first time. In ordinary operation, there's no need whatsoever to do this, but I wanted to try backing up my ebooks. Also, since writing this I wanted to confirm my suspicion that the current Amazon DRM scheme is more akin to Apple's FairPlay "speed bump" than a serious playback control technology.

In short, it is.

The Kindle connects as an ordinary USB mass storage device with a simple folder structure, containing four root-level directories:

  • Audible: audio ebooks? (empty in my case)
  • documents: ebooks
  • music (empty in my case)
  • system: Not exactly what it sounds like — it doesn't actually contain the operating system, only auxiliary data files used by system software. I suppose it's sensible enough not to let some clueless user bork their OS by accidentally dragging this file to the trash. (I suspect that there's a backdoor code that will mount the OS/firmware as well; at least, that's how I'd design this device if I were a developer and wanted to debug it.)

For each ebook, the documents folder contains at least one .azw, .azw1, or .tpz file, and usually a .mbp or .tan file that stores some auxiliary data. Your "clippings" file (containing excerpts that you highlight or note) is stored as a plain .txt file (yay).

Free samples and free public domain ebooks from Amazon are not DRM-restricted. Purchased books, of course, are.

Incidentally, no technology in the Kindle device prevents copying. As noted, the Kindle mounts as an ordinary USB mass storage device, and it is inherent in the filesystem abstraction that you can do simple things like copy the entire contents of the documents folder onto your hard drive. You can do it once or a thousand times, and no technology even tries to stop you. This is an inherent function of the type of device that Amazon has made.

What the files' DRM prevents, in theory, is "playing back" the files' content on some other device after it has been copied. But of course, it doesn't really do that in practice. Without going into details, there are downloadable programs on the Internet, widely available in source and executable forms, which can extract the contents of a restricted AZW file.*

So, in short, it's trivial for you to back up your ebook library. If you're a programmer, it's also pretty easy to write a script that will harvest your entire ebook library, shuck off the obnoxious DRM enclosure, and transcode the contents into some other format. Nontechnical users, unfortunately, don't have easy access to the DRM removal/transcoding step, although this may change as the transcoding software matures and distribution channels route around the legal jurisdictions where this software is banned.

Anyway, as I wrote in my earlier post, I'm hoping that the content production cartels will eventually realize that DRM serves Amazon's interests, not theirs, and abandon even the "speed bump" DRM currently in place. In the meantime, I've found that the value of having a dozen unread books in my bag at any given time, and being able to buy and read a book instantly at midnight on a Sunday, is sufficiently huge that I'm willing to make the compromise.**

*Even if this weren't true, people determined to infringe copyright for monetary or other gain will do so. DRM does not prevent the widespread, willful, uncompensated distribution of copyrighted content. The only thing that DRM does is prevent legitimate paying customers from getting the value from their books that they have been promised by electronic booksellers' use of the phrase "buy this book".

**A compromise, incidentally, that I was never willing to make with iTunes DRM. I suppose that the value I get in my life from reading greatly exceeds the value I get from music.

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