> I'd still like to understand the rationale for having the merchant > broadcast the transaction
There are several reasons for this: 1) P2P network sockets are a limited resource and bringing up connections to the network, whilst somewhat fast today, is not guaranteed to be fast in future. Passing transactions to the merchant for broadcast reduces the load on the P2P nodes because lots of thin clients aren't any longer connecting and disconnecting when sending. They only need to talk to the network when the user has received money. 2) Some users may not have network connectivity at all. For example, this happens quite often whilst traveling at Bitcoin conferences ;) The solution, which Andreas and I prototyped in Berlin together, is for the buyer to communicate only with the seller which can be done over Bluetooth or WiFi Direct or some other mobile radio protocol. Again, send only, but for the common case where you load up your wallet before setting out and then buy things, it works OK. 4) A longer term reason - in time, people may choose to not broadcast transactions at all in some cases. I think how network speed will be funded post-inflation is still an open question. Assuming the simplest arrangement where users pay fees, getting transactions into the chain has a cost. In cases where you trust the sender to not double spend on you, you may keep a fee-less transaction around "in your pocket". Then when it's your turn to pay, you use some unconfirmed transactions to do so. People pass around longer and longer chains of un-broadcast transactions until a payment crosses a trust boundary, at which point the receiver adds on their own transaction that spends back to himself but with a fee, and broadcasts them all together as a unit. In this way only people who genuinely need to fear double spends pay for security. ------------------------------------------------------------------------------ Keep yourself connected to Go Parallel: VERIFY Test and improve your parallel project with help from experts and peers. http://goparallel.sourceforge.net _______________________________________________ Bitcoin-development mailing list Bitcoin-development@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bitcoin-development