Bitcoin Take Over Threats- Coming $Trillion(s) bubble burst will demand world government intervention & cooperation [1] (Bernie Madoff is so much smaller)
- Selfish mining attack confirmed by skeptics
- Those who were anonymous lose it ex post facto, when tax & law enforcement attack a.k.a. "coin taint" the numerous non-anonymous [2]
- 51% attack because mining is concentrated in a few pools
- 51% attack because mining is ASICs concentrated and ASICs foundries could be purchased with unlimited fiat. Note also ASICs can't be re-purposed as PCs can, i.e. each ASIC only works for a specific coin design.
- 51% attack because mining is not funded with perpetual debasement (new coins) to remain proportional to market value, instead transaction fees can not scale to market cap because even debit cards & ACH charge a flat-fee not a percentage of transaction value. Thus the world's rich (denominated in coin) grow more wealthy relative to the income of the miners.
- Non-zero transaction fees allows cartel take over via Transactions Withholding Attack
- Pools can be attacked with Share Withholding Attack fixable with oblivious shares
- Blockchain requires increasingly powerful full clients as scale to billions of transaction, thus more centralization and vulnerability to 51% attack.
- Superior altcoin
So basically barring the first and the last, all the threats you are listing are related to the Proof of Work mining. Despiste what you are saying, I think Proof of Stake mining address these problems.
The first threat - government cooperation - is highly speculative and I prefer put my money on Bitcoin rather than on this eventually.
So it's boils down to: will Proof of Stake overtake Proof of Work. The market will decide. The only thing investors have to do is hedging by capturing the same portion of the PoS coin supply that they have in Bitcoin (Bitshares and NXT being the most serious PoS coins from my point of view)
I
refuted the security of Bitshares.
PoS and proof-of-primes (e.g. Primecoin) do not solve the anonymity take over Threat. See the 3rd item.
Proof-of-primes
can not be mathematically as secure as PoW. The
entropy security issue always applies to all the non-PoW systems.
Proof systems which attempt to do useful computational work
can not be secure.
PoS
can not redistribute new coin in way that
rewards individual effort and ingenuity as proof-of-work can. For example, I've explained that
stream microhydropower is the least expensive electricity on the planet. Of course any non-PoW coin can redistribute coins equally or based on share, but that is just Communism (a very failed economic concept of course!). Thus we are right back to needing socialism to redistribute coin from slow large capital to faster smaller capital for us. Otherwise the wealthy accumulate all of the wealth. I covered this in great detail in the MadMax thread. See the links in Errata section of the OP and my first rebuttal to blablahblah.
Proof-of-stake requires no significant computation thus runs on any PC, but it
can't be a coin of the masses because it can't distribute new coin in any competitive manner accessible to those only with a PC. Wealth is power law distributed¹ thus transactions will never do the job that socialism does to redistribute wealth to the masses and prevent the wealthiest 1% from owning everything. For money to not end up fiat where it can be debased top-down by socialism, the decentralized crypto-currency must be able to do the redistribution job that socialism is doing.
¹Dragulescu & Yakovenko. Exponential and power-law probability distributions of wealth and income in the United Kingdom and the United States
PoS means the elite control the transaction processing, i.e. the 51% attack is built-in by design. We are right back to same problem again. Only proof-of-work solves the Byzantine Generals Problem. See my first rebuttal to blablahblah.
Sorry.
P.S. I am confident
PoS is not secure. If I put some time on that, I bet I can write down a proof. Will do at some point in future.