Topic: ==== Eligius, please pay my 200+ BTC ==== (Read 12592 times)

Quote from: Luke-Jr on July 11, 2014, 12:27:59 AM

Sure he does. He could even 51% attack p2pool to get up to ~200% PPS (at the expense of everyone else).

Could you please explain a 51% p2pool attack in more detail? I mean, lot of people believe, that p2pool is the most decentralized mining option available, and you state, that a 51% attack could be done to p2pool?

An "obvious" one would be making it so nodes ignore a forked chain more than 'X' shares deep, if it all pays out to the same address (indicating somebody forked from the chain to build a longer one that only pays themselves), though all that you'd have to do to combat that is cycle through addresses when making your fork.

In other words, p2pool users would be mining a block which pays almost the entire reward to the attacker, even though they've only done 51% of the actual work.

The difference is a 51% attack on the p2pool chain would be immediately obvious to all miners monitoring it - p2pool finds a block, but no payment is made since the attacker has substituted their own btc addresses into the sharechain, instead of the legitimate miners.

In this event, I imagine miners would just jump ship, if a better solution isn't implemented by then. Until then, though, it still has its advantages.

The "obvious" defense is too easily countered by new addresses for each block. Addresses are zero cost.

DumDumz

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He tried something, he got caught,now he owes 400 BTC and is trying to refocus the discussion away from that fact.

Hunterbunter

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Quote from: Hunterbunter on July 10, 2014, 11:29:16 PM

Hmm, that makes sense to me. So, there is no way of fighting against mining centralization? I thought p2pool is a decent solution...

Sure, there's getblocktemplate, a decentralised client-server mining protocol.
Basically all the positives of p2pool without the negatives.
Just needs more time to finish implementing it...

The difference is a 51% attack on the p2pool chain would be immediately obvious to all miners monitoring it - p2pool finds a block, but no payment is made since the attacker has substituted their own btc addresses into the sharechain, instead of the legitimate miners.

In this event, I imagine miners would just jump ship, if a better solution isn't implemented by then. Until then, though, it still has its advantages.

Just like all the miners jumped ship from Arsbitcoin when it forked off the blockchain? Or when it shutdown?
Or like when they jumped ship when 0.8-based pools forked off the main bitcoin blockchain?
Or like when they jumped ship from Deepbit when it stopped mining valid blocks?

Sadly, most miners don't pay attention.

Maybe a marginal number don't pay attention, but enough do. In this event, the block chain is still uncompromised and only P2Pool is naffed.

Luke-Jr

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Quote from: Hunterbunter on July 10, 2014, 11:29:16 PM

Hmm, that makes sense to me. So, there is no way of fighting against mining centralization? I thought p2pool is a decent solution...

Sure, there's getblocktemplate, a decentralised client-server mining protocol.
Basically all the positives of p2pool without the negatives.
Just needs more time to finish implementing it...

The difference is a 51% attack on the p2pool chain would be immediately obvious to all miners monitoring it - p2pool finds a block, but no payment is made since the attacker has substituted their own btc addresses into the sharechain, instead of the legitimate miners.

In this event, I imagine miners would just jump ship, if a better solution isn't implemented by then. Until then, though, it still has its advantages.

Just like all the miners jumped ship from Arsbitcoin when it forked off the blockchain? Or when it shutdown?
Or like when they jumped ship when 0.8-based pools forked off the main bitcoin blockchain?
Or like when they jumped ship from Deepbit when it stopped mining valid blocks?

Sadly, most miners don't pay attention.

Hunterbunter

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Quote from: eleuthria on July 10, 2014, 09:30:51 PM

Sure he does. He could even 51% attack p2pool to get up to ~200% PPS (at the expense of everyone else).

Could you please explain a 51% p2pool attack in more detail? I mean, lot of people believe, that p2pool is the most decentralized mining option available, and you state, that a 51% attack could be done to p2pool?

An "obvious" one would be making it so nodes ignore a forked chain more than 'X' shares deep, if it all pays out to the same address (indicating somebody forked from the chain to build a longer one that only pays themselves), though all that you'd have to do to combat that is cycle through addresses when making your fork.

In other words, p2pool users would be mining a block which pays almost the entire reward to the attacker, even though they've only done 51% of the actual work.

The difference is a 51% attack on the p2pool chain would be immediately obvious to all miners monitoring it - p2pool finds a block, but no payment is made since the attacker has substituted their own btc addresses into the sharechain, instead of the legitimate miners.

In this event, I imagine miners would just jump ship, if a better solution isn't implemented by then. Until then, though, it still has its advantages.

DumDumz

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He tried something, he got caught,now he owes 400 BTC and is trying to refocus the discussion away from that fact.

eleuthria

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Hmm, that makes sense to me. So, there is no way of fighting against mining centralization? I thought p2pool is a decent solution...

Thanks eleuthria

I'm unable to think of a way to fix this problem, it's essentially the same problem as Bitcoin itself has when it comes to a 51% attack. If p2pool did something like limit the size of a sharechain re-org to only so many shares deep, it would work most of the time, but it would fail if there was ever any major communication issues between countries, essentially forking p2pool into multiple p2pools because they would refuse to come back to a consensus.

crashoveride54902

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Quote from: eleuthria on July 10, 2014, 09:30:51 PM

Quote from: eleuthria on July 10, 2014, 09:30:51 PM

Sure he does. He could even 51% attack p2pool to get up to ~200% PPS (at the expense of everyone else).

Could you please explain a 51% p2pool attack in more detail? I mean, lot of people believe, that p2pool is the most decentralized mining option available, and you state, that a 51% attack could be done to p2pool?

p2pool is like a miniature Bitcoin blockchain. If you had 51% of the p2pool hash rate, you could (more often than not) force your own shares into the sharechain instead of someone elses by forking it until your chain was longer. I'm not sure what, if any, precautions are present in p2pool to prevent somebody from purposely forking the sharechain in their favor.

An "obvious" one would be making it so nodes ignore a forked chain more than 'X' shares deep, if it all pays out to the same address (indicating somebody forked from the chain to build a longer one that only pays themselves), though all that you'd have to do to combat that is cycle through addresses when making your fork.

In other words, p2pool users would be mining a block which pays almost the entire reward to the attacker, even though they've only done 51% of the actual work.

Hmm, that makes sense to me. So, there is no way of fighting against mining centralization? I thought p2pool is a decent solution...

Thanks eleuthria

not really...in the end, big money will centralize it whether we want it to happen or not...unless the btc coders force them to decentralize idk

psahx

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Sure he does. He could even 51% attack p2pool to get up to ~200% PPS (at the expense of everyone else).

Could you please explain a 51% p2pool attack in more detail? I mean, lot of people believe, that p2pool is the most decentralized mining option available, and you state, that a 51% attack could be done to p2pool?

p2pool is like a miniature Bitcoin blockchain. If you had 51% of the p2pool hash rate, you could (more often than not) force your own shares into the sharechain instead of someone elses by forking it until your chain was longer. I'm not sure what, if any, precautions are present in p2pool to prevent somebody from purposely forking the sharechain in their favor.

An "obvious" one would be making it so nodes ignore a forked chain more than 'X' shares deep, if it all pays out to the same address (indicating somebody forked from the chain to build a longer one that only pays themselves), though all that you'd have to do to combat that is cycle through addresses when making your fork.

In other words, p2pool users would be mining a block which pays almost the entire reward to the attacker, even though they've only done 51% of the actual work.

Hmm, that makes sense to me. So, there is no way of fighting against mining centralization? I thought p2pool is a decent solution...

Thanks eleuthria

eleuthria

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Activity: 1750

Merit: 1007

Sure he does. He could even 51% attack p2pool to get up to ~200% PPS (at the expense of everyone else).

Could you please explain a 51% p2pool attack in more detail? I mean, lot of people believe, that p2pool is the most decentralized mining option available, and you state, that a 51% attack could be done to p2pool?

p2pool is like a miniature Bitcoin blockchain. If you had 51% of the p2pool hash rate, you could (more often than not) force your own shares into the sharechain instead of someone elses by forking it until your chain was longer. I'm not sure what, if any, precautions are present in p2pool to prevent somebody from purposely forking the sharechain in their favor.

An "obvious" one would be making it so nodes ignore a forked chain more than 'X' shares deep, if it all pays out to the same address (indicating somebody forked from the chain to build a longer one that only pays themselves), though all that you'd have to do to combat that is cycle through addresses when making your fork.

In other words, p2pool users would be mining a block which pays almost the entire reward to the attacker, even though they've only done 51% of the actual work.

psahx

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Activity: 154

Merit: 100