[Bitcoin-development] Double spend detection to speed up transaction trust

[Gregory Maxwell]

On Thu, Aug 4, 2011 at 6:10 PM, Stefan Thomas <moon at justmoon.de> wrote:
> Would network support like a MSG_DOUBLESPEND be better? I used to think
> yes, but looking at the reality of Transaction Radar, I'm not so sure.
> Nothing stops such a service from scaling up and connecting to thousands
> of random nodes (especially when the network itself grows bigger),

Except for the fact that such a party is a DOS attack on the network
which is already short on functioning listeners.  I don't have much
doubt that people doing the "connect to everyone" are already causing
harm. There are some nodes in .ru/.ua which aggressively connect to me
(instant reconnects if I hang up on them) which have never passed me a
transaction in all my available logs.

Alerts scale better— both can have a place in the ecosystem, they're
actually complementary: Alerts are vulnerable to filtering by sibyl
attackers but they have deeper network penetration and where filtering
doesn't prevent them you don't need a connection to hear them.