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Title: How do these Bitcoin transactions confirm so quickly? Post by: Jet Cash on August 13, 2018, 06:47:19 AM This video was made in October 2017, and the guy was shopping in a Tokyo supermarket, and paying with Bitcoin.
https://www.youtube.com/watch?v=W4J_myvNYG8 He seems to have had his transactions confirmed almost immediately, and I don't understand how this happened. I can see it working with the lightening network, but I don't think that was available then. Is it just that the shop is prepared to take a risk, and as long as the transaction was sent, they don't bother to wait for a confirmation? That seems to be a bit risky, as if it was sent as a no/low fee transaction, there must be a risk that it is never confirmed. Title: Re: How do these Bitcoin transactions confirm so quickly? Post by: ABCbits on August 13, 2018, 06:49:18 PM It's obvious the answer is they accept 0-conf/zero-confirmation, but most likely they do/check these things (since there's few second delay on the video) before the system decide to verify the transaction :
1. Check fee in the transaction is sufficient to get confirmed 2. Check the bitcoin network if there's double-spend attempt 3. Broadcast the transaction to many other nodes to reduce double-spend attempt chance But, there shouldn't be any problem with double-spend attempt if the "attack" transaction is broadcasted few seconds slower. More info https://bitcointalk.org/index.php?topic=423.msg3819#msg3819 (https://bitcointalk.org/index.php?topic=423.msg3819#msg3819) |