On 5 November 2013 23:06, Gregory Maxwell <gmaxwell@gmail.com> wrote:

On Tue, Nov 5, 2013 at 2:15 PM, Drak <drak@zikula.org> wrote:
> If I understand the issue properly, this seems like a pretty elegant
> solution: if two blocks are broadcast within a certain period of eachother,
> chose the lower target. That's a provable fair way of randomly choosing the
> winning block and would seem like a pretty simply patch.

uh. and so when my solution is, by chance, unusually low... I am
incentivized to hurry up and release my block because?

Yes, I saw the flaw as pointed out by Quinn so I then suggested two step solution:

1. Decide high or low by taking a the leading bytes from hash(alice)+hash(bob): above certain number we the rule is "higher wins", below a certain number the "lower hash wins"

2. Chose winner based on the higher or lower of hash(alice) or hash(bob) based on the rule coming from 1

Now you have a situation where you don't know the rules of the game in advance (whether high or low wins) until the hands are already dealt nor have any idea about how high or low Bob's hash will be since it's not based on target anymore, but on a hash of the blockhash so it makes it a guessing game.

You might have an unusually high or low hash, but then you have no idea whether higher or lower is going to win. So it is better for Alice to just broadcast the block.

What do you think?

Drak