Re: [Bitcoin-development] A statistical consensus rule for reducing 0-conf double-spend risk

2014-05-12 Thread Tom Harding
Sorry to run on, a correction is needed. A much better approximation requires that the rule-following minority finds the next TWO blocks, so the cost is (total miner revenue of block)*(fraction of hashpower following the rule)^2 So the lower bound cost in this very pessimistic scenario is .002

Re: [Bitcoin-development] A statistical consensus rule for reducing 0-conf double-spend risk

2014-05-11 Thread Tom Harding
Christophe Biocca wrote: > The problem is that since the rule > isn't enforceable, no miner will wait before mining on the longest > chain (which is the rational move), and you're back to where we are > now. Back up to the miner who decided to include a "seasoned" double-spend in his block. Let

Re: [Bitcoin-development] A statistical consensus rule for reducing 0-conf double-spend risk

2014-05-06 Thread Tom Harding
Christophe Biocca wrote: > it becomes trivial with a few tries to split the network into two > halves: (tx1 before tx2, tx2 before tx1). "before" implies T=0. That is a much too optimistic choice for T; 50% of nodes would misidentify the respend. > Tom Harding wrote: >>- Eventually, node

Re: [Bitcoin-development] A statistical consensus rule for reducing 0-conf double-spend risk

2014-05-03 Thread Christophe Biocca
Unfortunately this could fork the network permanently, which is much worse than a double spend. There's no magic way to have a consensus, so it becomes trivial with a few tries to split the network into two halves: (tx1 before tx2, tx2 before tx1). Some nodes in the middle will accept either block,

[Bitcoin-development] A statistical consensus rule for reducing 0-conf double-spend risk

2014-05-03 Thread Tom Harding
This idea was suggested by "Joe" on 2011-02-14 https://bitcointalk.org/index.php?topic=3441.msg48484#msg48484 . It deserves another look. Nodes today make a judgment regarding which of several conflicting spends to accept, and which is a double-spend. But there is no incorporation of these c