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Zero-confirmation Bitcoin transactions

• Animats 12y ago
  Well, yes, you can forward Bitcoins without risk this way. But it doesn't solve the real problem, which is selling something for Bitcoins that you can't get back if the Bitcoin transaction is rejected. One online gambling site that accepted zero-confirmation transactions was burned by double spends. The bettor would quickly respend any funds they lost, invalidating the payment. If they won, they let the Bitcoin transaction go through and accepted the winning payment. This new "zero confirmation" scheme wouldn't protect against that. It would just prevent placing a bet, winning, accepting the won amount, then canceling the original payment. Back to the drawing board, zero-conf people.
  • wlk 12y ago
    Well said, for those how would like to see similar example done using bitcoinj, this is the link: https://github.com/bitcoinj/bitcoinj/blob/master/examples/src/main/java/org/bitcoinj/examples/ForwardingService.java https://github.com/bitcoinj/bitcoinj/blob/master/examples/sr... Note lines 90-95, the comment explains when coins will be forwarded and how to change that behavior
  • drxzcl 12y ago
    It's not a new scheme, it's exactly how that "one online gambling site" does it. I wondered how they did it, so I figured it out, replicated it and wrote a blurb about it. It's a pretty neat trick to extend the "all or nothing" property to multiple transactions. For some very limited use-cases (like my admittedly contrived example), this is exactly what you want. Usually it's not. Usually you just have to wait. Honestly, bitcoin is not really suited for instant gratification things.