As a follow-up to my blog entry here regarding Amazon.com and MP3 Watermarking...
Alex Halderman over at the Freedom To Tinker blog yesterday posted an entry that seems to confirm the theory that Amazon.com is not individually tagging each MP3 file purchased and that any file downloaded with the same title is identical to that downloaded by another user:
Last week Amazon.com launched a DRM-free music store. It sells tracks from two major labels and many independents in the unprotected MP3 file format. In addition to being DRM-free, Amazon’s songs are not individually watermarked. This is an important step forward for the music industry.
Some content companies see individualized watermarks as a consumer-friendly alternative to DRM. Instead of locking down files with restrictive technology, individualized watermarking places information in them that identifies the purchasers, who could conceivably face legal action if the files were publicly shared. Apple individually watermarks DRM-free tracks sold on iTunes, but every customer who purchases a particular track from Amazon receives the exact same file.
The company has stated as much, and colleagues and I confirmed this by buying a small number of files with different Amazon accounts and verifying that they were bit-for-bit identical. (As Wired reports, some files on Amazon’s store have been watermarked by the record labels, but each copy sold contains the same mark. The labels could use these marks to determine that a pirated track originated from Amazon, but they can’t trace a file to a particular user.)
This is good news and I thank Alex and his friends for doing the dirty work and actually confirming these statements instead of just parroting them back and taking Amazon's word for it. The rest of Alex's blog entry provides good insight as to the risks -- legal, security and otherwise -- that swirl around the contentious topic of DRM. Please read the article in its entirety.