From: "Luke-Jr" <luke@dashjr•org>
To: Peter Todd <pete@petertodd•org>
Cc: bitcoin-development@lists•sourceforge.net
Subject: Re: [Bitcoin-development] The insecurity of merge-mining
Date: Wed, 1 Jan 2014 05:09:27 +0000 [thread overview]
Message-ID: <201401010509.27977.luke@dashjr.org> (raw)
In-Reply-To: <20140101045342.GA7103@tilt>
On Wednesday, January 01, 2014 4:53:42 AM Peter Todd wrote:
> On Tue, Dec 31, 2013 at 01:14:05AM +0000, Luke-Jr wrote:
> > On Monday, December 30, 2013 11:22:25 PM Peter Todd wrote:
> > > that you are using merge-mining is a red-flag because without majority,
> > > or at least near-majority, hashing power an attacker can 51% attack
> > > your altcoin at negligible cost by re-using existing hashing power.
> >
> > I strongly disagree on this isolated point. Using the same logic, Bitcoin
> > is vulnerable to an attacker at negligible cost by re-using existing
> > hashing power from mining Namecoin. Any non-scam altcoin is pretty safe
> > using merged mining, since any would-be attacker is going to have it in
> > their interests to invest in the altcoin instead of attacking it. It's
> > only the scam ones that want to pump & dump with no improvements, that
> > are really at risk here.
> >
> > The rational decision for a non-scam altcoin, is to take advantage of
> > merged mining to get as much security as possible. There are also some
> > possible tricks to get the full security of the bitcoin miners even when
> > not all participate in your altcoin (but this area probably needs some
> > studying to get right).
>
> You assume the value of a crypto-currency is equal to all miners, it's
> not.
>
> Suppose I create a merge-mined Zerocoin implementation with a 1:1
> BTC/ZTC exchange rate enforced by the software. You can't argue this is
> a scamcoin; no-one is getting rich. There's a 1:1 exchange rate so the
> only thing you can do with the coin is get some privacy. But inevitably
> some miners won't agree that enabling better privacy is a good thing, or
> their local governments won't. Either way, they can attack the Zerocoin
> merge-mined chain with a marginal cost of nearly zero.
Not necessarily. If Zerocoin was tied directly to Bitcoin proof-of-work, the
worst they could do is not-participate by mining empty blocks.
> OTOH if the Zerocoin scheme was implemented by embedding ZTC
> transactions within standard Bitcoin transactions - even without any
> attempt at hiding them - the attackers would need a 50% majority of
> hashing power to succeed. Of course potentially slow confirmations is a
> trade-off, but that's likely a perfectly OK trade-off in this case.
Potentially slow confirmation is also the only shortcoming of using Bitcoin's
proof-of-work directly.
Luke
next prev parent reply other threads:[~2014-01-01 5:09 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-29 18:53 [Bitcoin-development] Looking for GREAT C++ developer for exciting opportunity in bitcoin space Evan Duffield
2013-12-29 19:27 ` Matt Corallo
2013-12-30 23:22 ` Peter Todd
2013-12-31 1:14 ` Luke-Jr
2013-12-31 7:28 ` [Bitcoin-development] Merge mining Jeremy Spilman
2013-12-31 7:38 ` rob.golding
2014-01-04 8:49 ` David Vorick
2014-01-04 10:05 ` Jorge Timón
2014-01-04 10:08 ` David Vorick
2014-01-04 10:34 ` Jorge Timón
2014-01-01 4:53 ` [Bitcoin-development] The insecurity of merge-mining Peter Todd
2014-01-01 5:09 ` Luke-Jr [this message]
2014-01-01 5:25 ` Peter Todd
2014-01-03 19:14 ` Jorge Timón
2014-01-03 21:01 ` Peter Todd
2014-01-04 0:27 ` Jorge Timón
2014-01-06 15:44 ` Peter Todd
2014-01-09 17:19 ` Jorge Timón
2014-01-10 11:11 ` Peter Todd
2014-01-10 11:25 ` Peter Todd
2014-01-10 12:37 ` Jorge Timón
2014-01-10 12:29 ` Jorge Timón
2014-01-10 17:22 ` Peter Todd
2014-01-10 18:50 ` Jorge Timón
2014-01-03 5:11 ` [Bitcoin-development] Looking for GREAT C++ developer for exciting opportunity in bitcoin space Troy Benjegerdes
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