Quote from: hashman on May 21, 2014, 09:50:32 AM

Thanks for your reply iruu!
The very real problem you outline of centralization of miners is exactly the same or worse in a proof of stake system. If miners can work together to become a nefarious majority, so can forgers. In fact logistically it would be much easier for the forgers but that is a moot point: proof of stake offers nothing new here.

It offers orders of magnitude more security, because you need a big percent of market cap, not just mining power.

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Of course it is possible to rent hashpower or stake at cost. We all know that cost and so bury our TXs under an appropriate number of blocks. These are valuable resources so a market exists for them. I fail to see the difference between hashpower and stake in that regard. Remember also that the >50% attack is not >50% of all the hashing power (or stake) in the world, but only >50% of the current network rate.

https://blockchain.info/stats
Total Miners Revenue $2,052,572.14
Market cap (coinmarketcap) $ 6,305,819,442

So in a perfect market, you can take control of bitcoin's network, for a day, at a bargain price of $2,052,572.14 + $0.01. That's 0.0326%. You can wait a bit for the next halvening and it's going to be even cheaper!

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For a PoS coin this is much lower than half of market cap.

Ok. Yet I'm pretty sure it's at least two orders of magnitude bigger... one exchange node would probably be enough to dwarf bitcoin's security.

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If you wish to claim PoS is much much safer against 51% attack you need to outline an algorithm that closes the new holes introduced by PoS (deep chain re-orgs with old keys, resusing stake, good solution to choosing which stake gets which block) but also come up with some reason it is better (none is offered).

Maybe you should read the rest of my first post, and then later posts.

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(none is offered).

I'm pretty sure I have mentioned security.

Then there's also lack of wasted energy, capital, and smaller market supply, because miners needs to sell the majority of coins to fund their operations. Mining is effectively a tax on all bitcoin users, almost a billion a year. You could run a small country on that.

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Good point! However, how do you intend to incentivise forgers if not with coinbase rewards and fees? If you remove this "interest payment", do you think folks will still be interested? I don't.

You may have rewards or not, but they are an implementation detail and can be different in each coin, using PoS or not.