Re: [Bitcoin-development] Double-spending unconfirmed transactions is a lot easier than most people realise

2014-04-23 Thread Tom Harding
On 4/22/2014 9:03 PM, Matt Whitlock wrote: On Tuesday, 22 April 2014, at 8:45 pm, Tom Harding wrote: A network where transaction submitters consider their (final) transactions to be unchangeable the moment they are transmitted, and where the network's goal is to confirm only transactions all

[Bitcoin-development] Double-spending unconfirmed transactions is a lot easier than most people realise

2014-04-22 Thread Peter Todd
You may have seen my reddit post of the same title a few days ago: http://www.reddit.com/r/Bitcoin/comments/239bj1/doublespending_unconfirmed_transactions_is_a_lot/ I've done some more experiments since, with good results. For instance here's a real-world double-spend of the gambling service

Re: [Bitcoin-development] Double-spending unconfirmed transactions is a lot easier than most people realise

2014-04-22 Thread Tom Harding
Since no complete solution to preventing 0-confirmation respends in the bitcoin network has been proposed, or is likely to exist, when evaluating partial solutions let's ask what kind of network does this move toward? Does the solution move toward a network with simple rules, where the

Re: [Bitcoin-development] Double-spending unconfirmed transactions is a lot easier than most people realise

2014-04-22 Thread Matt Whitlock
On Tuesday, 22 April 2014, at 8:45 pm, Tom Harding wrote: A network where transaction submitters consider their (final) transactions to be unchangeable the moment they are transmitted, and where the network's goal is to confirm only transactions all of whose UTXO's have not yet been seen in