Subject: Re: [Bitcoin-development] From the forums: one-confirmation attack

From: Gavin Andresen <[email-masked]>
Date: Thu, 18 Aug 2011 13:36:05 -0400

Gregory said: "...if this causes people to wait less than the 6 blocks
that the software currently waits for before leaving unconfirmed
status then that would be sad."

People are already considering transactions 'confirmed enough' at less
than six blocks. I'm guilty, too-- 3 is/was the magic number for
ClearCoin.

And people are already experimenting with ways of safely accepting
0-confirmation transactions, like InstaWallet's "green" payments (sent
from a trusted-not-to-double-spend address).

Since there is definitely market demand for "as fast as possible"
confirmation, I'm thinking adding a placeholder to the RPC interface
might be a good idea.  Although after thinking about it some more,
maybe a signed integer "trust" rating for blocks/transactions would be
a better way of doing it...

RE: miners connecting themselves together in a semi-trusted "bitcoin
backbone"  :  agreed.

Matt submitted a patch to connect and stay-connected to a set of
nodes, but I complained about the implementation.  Seems to me the
networking code needs an overhaul, to implement a priority queue of
potential peers (trusted peers would be sorted to near the top of the
queue, peers you think are badly-behaved would be sorted to the
bottom, with lots of randomness so not everybody on the network is
trying to connect to the same set of peers). With peer rotation to
mitigate manipulate-time and other Sybil attacks.

-- 
--
Gavin Andresen