Reputation System Fights P2P Junk

yeejiun writes "Many of the files that are shared on p2p networks tend to be junk. Organizations such as the RIAA and music labels regularly pollute these networks with nonsense files masquerading as real music/video files. These junk files make it difficult for users to find what they want on such p2p networks. Some researchers at Cornell University have developed a reputation system called Credence, that works on the Gnutella network, allowing users to tell the good files from the bad ones."

Comments

Re:eDonkey

[daikokatana]

Indeed - but there is a big problem with that system. eMule recognizes the file hashes and reports them as fakse, but it stops after that.

For the past few weeks, I have been rewriting part of the eMule source to have the following changes:

1. I offer a valid file with a valid hash (no fake) 2. People try to download the file from me and move up fast in my queue 3. Once they download a chunk from me, the data I send them is invalid (generated random) 4. Since this part is invalid, they need to redownload it 5. Since they move up faster in my queue than others, they redownload the part from me. 6. etcetera...

To be honest - I want to sell this tactic, that's why I do it. And so far it works! I get loads and loads of requests and rerequests for files, so this is a perfect tactic to kill the download of valid files - reputation system or no reputation system.

Remember, the file is valid, but they'll get it much much slower and spend x times the bandwidth to get it. I have unlimited bandwidth (up/down) so I always win in the end.

If whatever organisation I sell it to employs this on a large scale, the network will be flooded.