Wednesday, May 31, 2006

Honor system for BitTorrent

Say a vidcaster wants to earn some money with his content, or a great, but canceled, tv-series wants to make a comeback by publishing the episodes on the web. They could try advertising, but aren't the irritating ads the reason why we don't watch TV anymore? Maybe they can ask for a small fee to download the shows, right after they are produced. But would people pay if the show is for download on the P2P nets a few minutes later? Surely DRM is no solution, who in their right mind pays for a crippled file, that might not play on your favorite mediaplayer or portable device. For independent content producers, hosting large video files will be a problem to. Even if the show becomes popular, the income will not be enough to pay the bandwidth-bill.

The cost of distribution can be avoided when using BitTorrent with your own, private, tracker. And by using fingerprinting instead of DRM, customers can play the file on any player that supports the codec, without restrictions.

What I propose is to distribute the files over BitTorrent in a video format that uses keyframes, like xvid and other MPEG4 codecs.
When seeding a file BitTorrent chops it up in small blocks, some of these blocks will contain a complete keyframe. The blocks containing those keyframes are not distributed over BitTorrent but send to the subscriber individually. The BitTorent program will then add those blocks to the publicly distributed blocks and then assemble the complete file. The difference is that a fingerprint is added to the keyframes, identifying the subscriber. The fingerprint is visible but only until the next keyframe comes along, usually within 30 seconds. So transcoding will not remove the fingerprint and trying to mask it will obscure the video.

The content providers use a service that takes care of the BitTorrent trackers, the finger generation and payment.
Users of this service buy credits which they can use for every video that's distributed by the service.
After downloading the fingerprinted keyframes, a certain amount of credits is deducted from their account. If a user breaks the rules, leaks a file, and gets caught, he loses all of his remaining credits. If there aren't any credits left, the user gets excluded from the service for a while.

The big pluses:
Bandwidth cost are reduced with BitTorrent. No DRM is used, yet illegal distribution is discouraged by the honor system.
If similar fingerprinting techniques are possible for other kind of codecs, like mp3, they might be distributed in the same way.