Quote from: NanoAkron on January 29, 2014, 12:11:15 AM

Quote from: Minthos on January 28, 2014, 11:36:08 PM

Quote from: NanoAkron on January 28, 2014, 11:29:16 PM

Quote from: coinrevo on January 28, 2014, 01:24:07 PM

Its not how bitcoin works, but its an interesting concept. Instead of having the whole world verify blocks, one could somehow use nodes in some proximity. One could call it local web of trust.

One worry is the bar thinks its getting paid because it's seeing false confirmations, when in reality it's giving away drinks for free because the transactions are never getting relayed to the rest of the network.

Nope. A "confirmation" is a valid block with the transaction included, and a valid block includes a proof of work. The proof of work is far too valuable to waste trying to double spend in a bar.

Except for 2 things: in rapid low-value retail environments where we're told 0 conf should be ok, and I know bars that turn over £2,000+/night. Plenty of easy pickings if you spoof a few confirmations by pretending to be the rest of the network.

Are you aware that the block reward is currently worth 19200 USD? That's how much it costs to spoof a single confirmation. Nodoby is going to do that just to get a few free drinks in a bar.