Re: [Bitcoin-development] Possible attack: Keeping unconfirmed transactions

2014-06-10 Thread Raúl Martínez
I believe that the Payment Protocol works that way, the merchant broadcast the Tx. El 10/06/2014 13:23, Chris D'Costa chrisjdco...@gmail.com escribió: I wonder if Raul is mistakenly under the impression that the transaction only reaches the Bitcoin network via Alice? In which case the premise

[Bitcoin-development] Possible attack: Keeping unconfirmed transactions

2014-06-06 Thread Raúl Martínez
I dont know if this attack is even possible, it came to my mind and I will try to explain it as good as possible. Some transacions keep unconfirmed forever and finally they are purged by Bitcoin nodes, mostly due to the lack of fees. Example: - Alice is selling a pizza to Bob, Bob is

Re: [Bitcoin-development] Possible attack: Keeping unconfirmed transactions

2014-06-06 Thread Toshi Morita
From what I know, Alice does not know to which node Bob will broadcast the transaction. Therefore, Alice cannot intercept the transaction and prevent the rest of the network from seeing it. Toshi On Fri, Jun 6, 2014 at 3:02 PM, Raúl Martínez r...@i-rme.es wrote: I dont know if this attack is

Re: [Bitcoin-development] Possible attack: Keeping unconfirmed transactions

2014-06-06 Thread Raúl Martínez
Alice does not intercept the transaction, she only saves it and expect that it will not be confirmed (because has 0 fee for example). Also using the Payment Protocol I believe that Alice is the only person that can relay Bob's transaction. Source:

Re: [Bitcoin-development] Possible attack: Keeping unconfirmed transactions

2014-06-06 Thread Pieter Wuille
Whenever you do a reissuing of a transaction that didn't go through earlier, you should make sure to reuse one of the inputs for it. That guarantees that both cannot confirm simultaneously. On Sat, Jun 7, 2014 at 12:21 AM, Raúl Martínez r...@i-rme.es wrote: Alice does not intercept the