I'm at the Aspen Institute right now talking about Bitcoin and I mentioned the perils of starting an alt-chain based on proof of work that pool operators might attack; funny synchronicity! Peter On Mon, Jul 15, 2013 at 2:29 PM, Peter Todd wrote: > On Mon, Jul 15, 2013 at 03:05:52PM +0200, Jorge Timón wrote: > > One way sacrifice (btc to zerocoin) is a non-issue since there's no > > modification required for bitcoin and you can't do anything to prevent > > it anyway. > > The controversial thing is sacrificing something outside bitcoin's > > chain and new btc appearing. > > Which is why I'm not proposing that. > > > On merged mining. It is true that "merged attacking" the other chain > > is free, but it is still more profitable to just follow the rules and > > mine the other coin!! > > If someone considers that something he can sell in a market for btc is > > "negative value"...well, he's just dammed stupid. Proof of work is > > designed for rational actors, if you stop assuming miners are more or > > less rational everything falls apart. It is possible that the "extra > > value" is too little for some miners to bother. But the extra costs of > > validating something else are so little compared to chance-hashing > > that miners not merged mining namecoin right now are just stupid > > (irrational agents). You can merged mine and sell for btc right away. > > You are assuming value is the same for everyone - it's not. > > If I mine in a jurisdiction where zerocoin is banned, and the blocks I > mine are public, the value of zerocoin blocks to me are at best zero. > Equally it would be easy for the local authorities to ask that I merge > mine zerocoin blocks to attack the chain - it doesn't cost me anything > so what's the harm? I may even choose to do so to preserve the value of > the coins I can mine legally - alt-coins are competition. > > Incedentally keep in mind it is likely that in the future pools will not > allow miners to modify the work units they receive in any way as a means > of combating block-withholding fraud; there may not be very many people > willing or able to honestly merge-mine any given chain. > > Proof-of-sacrifice can be done in a way that is opaque to the master > blockchain by creating txouts that look no different from any other > txout. Hopefully not required, but it would be a good strategy against > censorship of sacrifice-based chains. > > > On prime proof of work...for me it's interseting only because it's > > moving towards SCIP-based mining but that should be the goal. Like > > Mark said, "let's cure cancer" while mining. That would end all > > "mining is wasteful" arguments about this great security system. This > > would make Ripple's consensus mechanism less attractive. People > > talking about new scrypts harder to ASIC-mine when that's the elephant > > in the room... > > Sorry, I'm going off-topic. > > SCIP-based merged mining for the win. > > SCIP is for now a dream. Give it a few more years and see how the > technology shakes out. > > -- > 'peter'[:-1]@petertodd.org > 00000000000000582cc323897a582e9368a5c3dfbcdcf73e78b261703e1bd1ba > -- ------------------------------ [image: CoinLab Logo]PETER VESSENES CEO *peter@coinlab.com * / 206.486.6856 / SKYPE: vessenes 900 Winslow Way East / SUITE 100 / Bainbridge Island, WA 98110