As far as I can tell, this network would have exactly the same level of security as a hypothetical Bitcoin network in which miners have 100% control over everything.
I disagree:
*It would be much less expensive to attack the network via a spam attack, which will result in a larger number of successful double spend attacks -- even if there is no hard coded transaction volume limit, miners will self-impose some limits due to the costs of signing transactions, and the costs of broadcasting transactions.
*The blockchain bloat will result in higher transaction costs, which will push people into using more off-chain services. The prevalence of off-chain services will entice scammers to open their own services, which will result in additional financial theft/loss
*This will give power to mining
pools, not miners. A pool acting maliciously will have control over Bitcoin for a very long time under your proposial, while if today's miners had control over Bitcoin, then miners would have the option of quickly leaving a pool at the first sign of malicious activity. Look at what happened to ghash when they started to find nearly 50% of the blocks.
For those who believe that Bitcoin is ruled by miners in this way, I put forward the following questions:
- If Bitcoin was intended to be ruled by miners, then why didn't Satoshi design Bitcoin as I described above? It'd be far simpler and better.
[/quote]Probably primarily because the blockchain bloat would make it very expensive to use Bitcoin.
- In this design, what incentive do miners have not to collude together in order to create more coins than originally planned, or to steal coins from people? Maybe they wouldn't want to risk causing people to lose faith in the system, but whenever there is any possible justification for such action (deflation, stolen coins, etc), why wouldn't they jump at the chance?
The miners do not have 100% control over Bitcoin. However they do have a great amount of influence over Bitcoin. The miners provide security to Bitcoin transactions, which is partially why merchants are willing to accept bitcoin as payment, which is what gives bitcoin value.
I would speculate that, as of 2-3 years ago, if say 75% of the miners (yes this is dangerously low) were to suddenly announce that they are going to start mining on a forked version of Bitcoin that has a maximum block size of 2MB and/or that changes the security of Bitcoin that is reasonably more secure, as of a block ~2 weeks in the future, that merchants, users (and "full nodes") would rush to upgrade (yes this is also a dangerously short amount of time to upgrade). The reason being is that this
really does not change Bitcoin all that much, all the
important qualities of Bitcoin would still be intact, and not upgrading would result in significant decline in security (also upgrading would result in ~the same amount of security). The miners are not unlike "employees" of the Bitcoin network, and this kind of situation would not be unlike an employee (or a group of employees) requesting a change in the way that they work, that is not unreasonable, and the boss (the network and economy) would reasonably allow this.
On the other hand, if 75% of the miners were to suddenly announce that they are going to start mining on a forked version of Bitcoin that changes the inflation schedule then the entire economy would most likely ignore any blocks generated on this branch.
- In the above design, what is the point of the mining chain at all? Wouldn't it be better to carefully select 20-40 extremely trustworthy entities to do the signing? In light of this, how do you justify any of Bitcoin's design?
Who is trustworthy and who is not trustworthy can change over time. Someone who has processed 50k
BTC worth of withdrawals one day, might decide to accept a large payment in exchange for promoting a website that he knows will scam thousands of
BTC the next day. The small number of entities that dominate the mining pool industry are trustworthy today, but if any of the mining pool operators were to start to misbehave then it would be trivial for the owners of the mining equipment to point their miners to a different pool.
Additionally, the owners of mining equipment need to post a bond via the price of their miners to not do things that will be damaging to Bitcoin.
In reality, Bitcoin is not ruled by miners because full nodes will ignore blocks that actively break the rules, no matter how many miners support such blocks, and full nodes can (and must) change the PoW function if miners are maliciously blocking or reordering transactions.
It is essentially
impossible to prove that miners are maliciously blocking transactions, especially with blocks being as full as they are today. The reason for this is due to pools can accept payment for transaction fees separately (and/or in addition to) from the transaction.
The change that is generally wanted by the miners (larger maximum block size) are also generally wanted by most of the economy, so the nodes would really have no reason to reject blocks that break the specific rule of the maximum block size. In fact, I have really not seen any reasonable argument as to why the maximum block size cannot be raised (to address the issue of large transactions that take a long time to validate, a simple solution might be to set the maximum transaction size to say 250kB -- although this may not solve the issue as I do not fully understand the problem).
Changing the way that blocks are mined is almost certainly going to result in overwhelming rejection by the economy. One reason is that the owners of ASIC miners are also deeply connected to other parts of the economy. Another reason would be that such alternate method of mining would be untested in securing any large sum of money and large volume of transactions, and because it would be
horribly centralized.