On Sun, Dec 21, 2014 at 06:10:47PM +0000, Adam Back wrote: > Yes you could for example define a new rule that two signatures > (double-spend) authorises something - eg miners to take funds. (And > this would work with existing ECDSA addresses & unrestricted R-value > choices). > > I wasnt really making a point other than an aside that it maybe is > sort-of possible to do with math what you said was not possible where > you said "This [preventing signing more than one message] is > impossible to implement with math alone". Introducing a bunch of clever ECDSA math doesn't change the fact that the clever math isn't what is preventing double-spending, clever economics is. Just like Bitcoin itself. No sense getting people potentially confused by a bunch of complex equations that aren't relevant to the more fundemental and much more important principle that math alone can't prevent double-spending. -- 'peter'[:-1]@petertodd.org 00000000000000001bc21486eb6e305efc085daa6b9acd37305feba64327342e