shieVae4I
To put my argument in context: consider IRC. An economically motivated BFT system would give the IRCops and channel ops some kind of quantified share of power that they stand to lose if they defect. But doing that, I think, would not just be a difficult programming exercise; it would also undermine the ops' intrinsic motivation and lead to a worse environment.
So the likes of Bitcoin work well if the protocol is designed for (game-theoretically) selfish participants whose interests lie mainly in the number going up. But that's a very narrow niche. Your genealogy site would probably suffer if it had a "number of family names added" counter and the users' status was measured entirely by such a number.
> Weighted users.To prevent Sybil attacks, Algorand assigns a weight to each user. BA⋆is designed to guarantee consensus as long as a weighted fraction (a constant greater than 2/3) of the users are honest. In Algorand, we weigh users based on the money in their account.
That 2/3 is your n=3f+1 right there. It's just that, as I said of PoS in general, the n is based on coin holdings.
This is not controversial, as the authors of Algorand are completely aware of the limitation:
> Most Byzantine consensus protocols require more than 2/3 of servers to be honest, and Algorand’s BA⋆ inherits this limitation (in the form of 2/3 of the money being held by honest users). BFT2F [35] shows that it is possible to achieve “fork∗-consensus” with just over half of the servers being honest, but fork∗-consensus would allow an adversary to double-spend on the two forked blockchains, which Algorand avoids.
It's just the Byzantine mechanism that happened to win. If anything, its innovation is that its n is based on hash power, not on number of users or nodes.
And the cost? Having to drag an immutable database around that can't be simplified; and, obviously, the opportunity cost of all the energy that's being used to support the consensus.
The game theory part is likely to be inexorably intertwined with the cryptocurrency part. The incentive to defect is blunted by people's investments, either in terms of hash power machines (for PoW) or in coin holdings (PoS). It would be very difficult to construct something that would be self-replicating/hype-incentivizing but not reward early comers the same way.
Isn't that a "they laughed at Galileo" argument?
They thought the Internet was snake oil. They thought Napster was snake oil. They thought BitTorrent was snake oil. ... but they also thought Pixelon was snake oil.
That's likely a Long Now reference: https://blog.longnow.org/02013/12/31/long-now-years-five-dig...