I had been reading up on Proof of Stake and the advantages and disadvantages. As if I am correctly informed, it is planned to change from PoW to PoS in the near future, using Casper. I had also been reading on why they would do so Why Does ethereum plan to move to proof of stake
I am actually wondering, why they did not created Ethereum right away on proof of stake, as nextcoin. Anyone any ideas?
I see two points why this could be the case, but they are only based on my intuition.
The first one is that the distribution of coins is not decentralized any more. In a PoS no new coins are generated during the creation of a block. Hence all coins have to be distributed via one or more central authorities. By switching to PoS at a later point in time a rather large amount of ether coins has already been distributed among all participants of this blockchain.
The second reason is the amount of influence one party with a rather large share of all ether coins can have a significant impact on those transactions that can enter the blockchain. In PoS those with the most coins have a higher influence on deciding which transactions are to be minded, compared to Proof of Work (PoW) where the computational power is the key factor (again: PoS ONLY requires a lot of ether coins, no computational power). This could allow a wealthy party that owns many coins to prioritize certain transactions and never include (and thus potentially excluding) specific transactions.
I see these two problems with a PoS beeing used in a blockchain upon the very beginning of it, espcecially because they accumulate each other.
I hope that helps you a lot. Feel free to correct me if I am mistaken or bring up more reasons.
A basic answer is that Casper was not ready (and Proof of Stake theory back then was lacking maturity).
Vlad Zamfir has some posts on his Medium about The History of Casper, starting with Chapter 1.
2 commonly cited problems with Proof of Stake are:
Chapter 2 concluded with the status on these problems and the path forward:
With the nails in the nothing-at-stake and long-range attack coffins completely hammered in, we were ready to start choosing our slashing conditions.
The next chapter will document what we learned from our first struggles to define a consensus protocol by specifying slashing conditions. I’ll also tell you about what we learned from talking with fine people from our space about our research. The game theory and economic modelling story presented here will continue developing in Chapter 4.
