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First of all I want to preface my comment with the disclaimer that proof of stake is nonsense in many ways (vulnerable to coordinated bribery attacks - we don't
by openfuture 5y ago
First of all I want to preface my comment with the disclaimer that proof of stake is nonsense in many ways (vulnerable to coordinated bribery attacks - we don't know how to coordinate well enough to execute them yet but the math checks out, also plutocracy..)
However it is a pretty expedient way to get something out the door fast (it's literally the simplest form of anti-sybil you can make and a cryptocurrency is anti-sybil + consensus).
So given that we accept proof of stake as a good way to prototype different approaches then a cryptocurrency that meets you criteria is the avalanche cryptocurrency (AVAX).
The way it works is via "stochastic gossip", whenever there is a conflict (double spend or some kind of decision problem where a node is unsure what is reality) then a consensus "game" is started. The way the game works is that you sample some reasonable sample of peers in the network (say 30-40 peers) and ask them "is A or B the legal state of the world?", now an honest participant will naively believe whatever the majority decision is.
Due to how stochastic probability stuff works the network will converge if you repeat this game sufficiently often. The idea is that if the initial state is 60% think A is the correct transaction then after a few rounds (they do 17 rounds which is overkill, you get like nine nines of probability or something) the whole network will have come to that conclusion (each time you run a round of the game the majority will _probably_ grow, eventually only the byzantine nodes are still saying B and if they are not the majority then all conflicts are solved).
Now bear in mind, there are some drawbacks, if someone is stubborn or does the opposite of what they should then maybe they can have some outsized influence, but in general this works pretty well and you can have a _lot_ of nodes participate in the network (much much more than in nakomoto consensus due to the different nature of the consensus mechanism). Furthermore you get finality in 3 seconds (even with the 17 rounds) so that is also quite nice (if you want to reach VISA level of transactions...
A validator in the avalanche network doesn't need some crazy hardware either.. a raspberry pi is fine, the limitation is you need the machine to be online 80% of the time they stake for.
That is one solution. There are others. For example amoveo, which is proof of work BUT it solves the second order byzantine fault tolerance problem (also known as the "oracle problem") which means that you can account for externalities (like energy usage) and throttle the mining rewards or adjust parameters in response.
I am working on a very raw but next-gen project myself, it's called datalisp (I wrote a very bad "whitepaper" in one sitting a couple of weeks ago... it's at datalisp.is - there is a telegram channel.. we're trying to figure out a lot of hard problems and we'd rather show than tell so if the whitepaper is somewhat up your alley then there is a lot more elaborate stuff happening in the channel).
The point of what I am saying is: if we want to kill bitcoin then the simplest way is to just make a better solution and change the narrative around the whole scene. I hate all this nonsense proof of stake ponzi nonsense, if a cryptocurrency is well designed then there is no advantage from being an early adopter (i.e. we solve byzantine fault tolerance _AND_ tragedy of the commons).
Please don't shit all over those of us who want to solve hard problems in a good way just because there's a bunch of assholes trying to get rich quick.
- mratsim 5y agoThe bribery can be solved with slashing and making it economically unviable to cede to bribery. Regarding plutocracy, it depends on proof-of-stake vs delegated-proof-of-stake. In one, everyone can become a staker and earnings are spread to all, in the other, some stakers are elected and earnings will be concentrated to them. Proof-of-work has inequality issues: - economies of scale for those that have the capital to rent a power plant and a large datacenter in a location with cheap electricity and/or cheap cooling. - latest ASICs / GPUs access at scale.
- openfuture 5y agoSlashing doesn't solve anything, I don't think you've studied how the attack would work. Proof of work that doesn't solve second order byzantine fault tolerance cannot account for externalities and suffers from the issues you mention. I agree that neither "solution" is all that great, my project is neither proof of work nor proof of stake.
- mratsim 5y ago> I don't think you've studied how the attack would work. It's my day job to implement proof-of-stake https://github.com/status-im/nimbus-eth2/pull/865 https://github.com/status-im/nimbus-eth2/pull/865
- openfuture 5y agoHow is that pull request relevant to our chat here? By the way I don't think it's a good argument to say that your job depends on proof of stake being secure and therefore it must be secure (or "therefore you would know if it wasn't"). The coordinated bribery attack can be done by having people stake on a different chain until a majority is reached and then softfork and slash the minority. If you don't believe the attack will work why not collect the bribe (since the defecting can be done anonymously / out of band) and if you believe it will work then you'd rather be on the winning side. ^ This is a rough sketch of the argument. As I said, it's hard to implement since you need an oracle to decide whether to pay the bribe, so it can only be done if you have second order byzantine fault tolerance and a few constructs. I believe we will see such attacks in this decade though (but ofc it only works if the PoS network is actually decentralized and it will keep working until the network becomes centralized).