Slashdot Mirror

← Back to Stories (view on slashdot.org)

Researchers Create Selfish BitTorrent Client

Posted by ryuzaki0 on from the surprised-it-took-this-long dept.

An anonymous reader writes "Researchers from the computer science department at the University of Washington have released BitTyrant, a new BitTorrent client that is designed to improve download performance via strategic selection of peers and upload rates. Their results call into question the effectiveness of BitTorrent's tit-for-tat reciprocation strategy which was designed to discourage selfish users. Clients are available for Windows, OS X, and Linux."

6 of 281 comments (clear)

  1. Not necessarily good by grimsweep · · Score: 4, Interesting

    Selfish selection of peers can lead to cliques of clients on the same network. Tit-for-tat has been proven as a highly effective strategy in games resembling the iterated prisoner's dilemna, but it can be defeated when a large enough group of of agents cooperate. This link has more.

    1. Re:Not necessarily good by ratboy666 · · Score: 4, Interesting

      But the ISP wants to encourage the development of such cliques. It can be directed to keep traffic inside the ISPs bounds.

      Interestingly, if bittorrent clients start "cheating", ISPs will be happier, and you will see less throttling.

      Ratboy

      --
      Just another "Cubible(sic) Joe" 2 17 3061
  2. Even better...downloading without ever uploading by meese · · Score: 5, Interesting

    Some folks at ETH Zurich took it one step further, and wrote a client - BitThief - that doesn't upload and yet still can download as fast as a regular client. This is especially valuable in countries that define copyright violation to be the uploading of content.

  3. Re:Not really selfish by hal2814 · · Score: 4, Interesting

    "But it prioritizes users with high upload/download speeds. It's better the way it's now - everybody gets their files."

    I disagree to an extent. What is high upload/download speed to one node is not neccessarily high upload/download speed to another node. It just depends on the network topography. It's possible for a DSL-connected node to have a faster upload/download connection to a node on a dial-up line than a T3 if the dial-up connection is significantly closer from a network standpoint. If done properly, prioritizing based on uploads could lead to more regionalized torrent relationships. Such a setup still has its downsides but I'm not convinced it's worse or even unfair.

  4. Re:leechers by Nasarius · · Score: 4, Interesting

    Not rare, it's extremely common on private sites with specialized material. I've had trouble raising my ratio above 0.85 on DIME, in spite of having 250KB/s upload. It's annoying, but there's not much you can do about it.

    --
    LOAD "SIG",8,1
  5. Emule / Edonkey has this by Deathlizard · · Score: 5, Interesting

    Emule has a system like this, and it basically slows everything down in the name of fair sharing. It takes absolutely forever to start downloads, since you're stuck in a vicious "chicken and egg" circle of "I can't upload anything to download" and "I can't download anything to upload".

    As it stands, Bittorrent is how the Edonkey protocol used to be before ratio systems were added to the clients; Fast. After Edonkey started adding anti-leech systems to the clients, the speed went into the toilet, and the queues started skyrocketing.

    I suspect that if this catches on, you can kiss 300kb's downloads goodbye.

    --
    In Soviet Russia, Trojan exploits YOU!