Virus writers seem to like this technique, uploading garbage to usenet. (50Kb files pretending to be a feature film, etc). I've always wondered why movie studios didn't do more of that.
Virus writers seem to like this technique, uploading garbage to usenet. (50Kb files pretending to be a feature film, etc). I've always wondered why movie studios didn't do more of that.
For arbitrary data you could possibly have a rating/tagging system. I guess the content industries could fudge the votes, but if the votes were tied to identity/pseudonyms they'd have to be clever to beat any kind of data analysis.
The effectiveness would probably depend on how many garbage alternatives you provided, and how sophisticated/varied their uploading is. Too many bad files and voting and signing might not be practicable, and you'd have to resort to some kind of automated spam-detection. White-listed sources are workable in the worst case, but I'm sure there would be other, better ideas around.
Essentially, the way it works is that for a given group there are two keys: A private key `P` (that only the group has), and a public key `Q` (that everyone has). For a file `F` the "signature" is the output of some function `sign(P, Q, F)`. The function `sign` is specially chosen so that the output can be validated without access to `P`, but cannot be efficiently forged without it.
As other posters have pointed out, this means that if `P` is kept secret then all signed releases can be authoritatively linked to the people who provided them. Finding `P` on someone's thumb drive is a smoking gun. To be honest, I don't think this would be a big worry, but I'm not in the scene and I don't know how the people in it think.
That said, a third party could add a signature. But in practice a cryptographically secure signature isn't even needed. It boils down to a reputation system, so that you can associate a torrent file with quality and this has already existed since forever on sites like the piratebay in the form of uploader usernames. A lot of torrents are uploaded by the same users, users who have a history of quality torrents. In contrast, a hollywood uploader would never have any actual quality torrents in the account history. So in conclusion, this problem was already solved ages ago.
http://news.bbc.co.uk/1/hi/2962475.stm
I still have a copy of the file somewhere.
That's half the story. Piracy is a hard habit to break - even when it does get easy to get content cheaply, some people take a while to come around.
It definitely works on usenet - virus spam can make some things impossible to find.