>You can have that type of finality with centralized protocols built on top of the Bitcoin blockchain — Lightning Network being the standout example.
Whats the point? No one wants that beside that LN needs BTC on chain Tx which if you dont arbitrary define as final after some blocks makes it exactly the same - not final.
PoS/PoW is rather irrelevant. we already have solutions to make blocks/ledgers final its doesn't need PoW or PoS its just a properties that BTC doesn't have because it was designed without. There is no fundamental reason why it cant have it.
I don’t quite catch your point. The chances your brain continues functioning over the next twelve minutes is not 100%, but 100% less some infinitesimally small fraction. 99.999999...% is as close physical reality ever comes to 100%.
> PoS/PoW is rather irrelevant
It’s an incredibly relevant fact that PoS blockchains pos1, pos2, pos3 cannot be compared without overtly trusting central authorities to give you the “correct” answer. Conversely, the PoW blockchains pow1, pow2, and pow3 can be objectively ranked by cumulative hashrate using simple mathematical comparisons.
Contrary to popular belief — and despite the endless handwaiving PoS acolytes engage in over social media — PoS blockchains continue to lack a meaningful answer to this predicament which doesn’t boil down to overtly trusting central authorities. Which begs the question: why do they need a blockchain at all?
All block chains in practice require trusting central authorities (trust the code, trust the protocol, trust the math behind it, trust the hardware, trust people to honor their off-chain transactions, trust authorities to help when they don't etc.) so this whole fantasy about 'trustless systems' is meaningless anyway.
You can't create trustless electronic systems for humans. There is simply too much complexity in even the simplest hardware and software for any single person to be able to understand without trusting others. And this doesn't just apply to the 'unwashed masses', but to every single CS researcher, OS programmer or Linus Torvalds.
This is blatantly false. Bitcoin doesn't require anything at all besides the idea of a most work chain humanity produced. You just pick it and that's it. You cant pick wrong, there is no chain bigger.
All other cryptos are a fantasy and cannot provide any comparable guarantees.
It happened multiple times that a longer change was discoed shortly after. So in reality you have to wait some blocks to reduce the risk of a longer chain to almost zero.
Also the trust you missed is that you have to TRUST that at least 50% of the work is produces and controlled (pool owner) by honest humans, because if not they could collude and re-org/double-spend. which essentially means you will pick the wrong chain because they make you think its the longest while secretly mining a longer chain that will eventually repalce the once you picked. There is absolutely no way you would know before its to late so you blindly trust that from an unknown number of people the majority is honest.
If you take mining pools into account you trust a hand full of people who control them.
>All other cryptos are a fantasy and cannot provide any comparable guarantees.
Obvious nonsense, other tech has defined finality. Not pick the longest and if a longer shows up later you switch. These systems provide MORE guarantees.
How do you, personally, know that the chain is correct? Have you ever checked the hashes? Have you ever checked the transactions? Have you ever proved that the math they use is correct? Have you ever read the code for any BTC client?
You're trusting an awful lot of assumptions much more complex than 'the longest chain is right'.
How do you ensure that you got the correct code? Without the correct consensus rules that are encoded in the software, you can't be sure if the blockchain you are following is the right one.
> PoS blockchains pos1, pos2, pos3 cannot be compared without overtly trusting central authorities to give you the “correct” answer.
I have seen you make this point before on here but I don't see how that is true. Can you elaborate? Don't PoS chains typically choose forks based on how much is staked? Last time we discussed this you never explained what is wrong with that approach.
When the PoW chain ‘pow’ forks into pow1 and pow2 with both sides claiming to be the original ‘pow’, the general public can compare the cumulative hashrate of pow1 and pow2 to ascertain legitimacy (see: Bitcoin v Bcash, 2016).
In PoW, external input to the system — electricity — powers hashrate. Electricity is altogether foreign to the context of cryptocurrency, and by necessitating the wasting of electricity on one fork over another, PoW consensus systems ensure miners can vote on only one side of a fork without bearing additional costs.
When the PoS chain ‘pos’ forks into pos1 and pos2, however, with both sides claiming to be the original ‘pos’, there is no hashrate to base our decision on. External inputs are never burned in any PoS chain’s forward progress.
If a Bitcoin v Bcash political fork were to unfold in a pure PoS context, the general public would be faced with a situation where both pos1 and pos2 chains were equally secure. If pos1 claimed to be the rightful heir to the ‘pos’ title while defensively slashing pos2 sympathizers, it wouldn’t harm pos2’s ability to make forward progress on the pos2 chain while pos2 also slashes pos1 sympathizers and equally claims to be the rightful heir to the ‘pos’ title.
It’s as if an OSS project forked with both forks claiming to be the real thing. If both sides are steadfast, it is ultimately up to the public to pick winners and losers based on nothing besides social signaling. See: 2015-2017 block size debate in Bitcoin for pitfalls to this.
Notice how no math is involved whatsoever in the decision to pick pos1 over pos2.
Notice how human intervention is inherently required to reach a decision as to which side of the pos1/pos2 split is given title to ‘pos’.
Pure PoS consensus is substantially similar to Git repos. If people are just going to trust a nebulous human hierarchy to resolve disputes like this, then the system is de facto permissioned, and a public blockchain isn’t required.
I don't understand how the situations you are describing are different between PoW and PoS.
In either case, after a fork, sympathizers of chain A or chain B will start mining/staking on the chain they like.
In either case, members of the public who just want the chain with the most security can pick the one with the most energy burned or most coin-days staked (that's the "hash rate" equivalent/external input with which to base your decision on).
What is the difference? How is human intervention inherently required in the PoS case any more or less than it's required in the PoW case?
If “coin-days staked” is massively higher on one side of a PoS chain fork, that doesn’t impact the other side’s security in the way PoW hashrate imbalances would.
To use a real world example, Bitcoin PoW mining consumes in excess of 100 Terawatt hours of electricity per year. If Bitcoin were to undergo a repeat of 2016 today, and the Bcash blockchain were to be serviced by miners consuming less than 10% of the energy spend of the incumbent (Bitcoin), Bcash could be easily 51% attacked.
But in the PoS corollary to Bitcoin v Bcash, coin-days staked would have no bearing on Bcash’s ability to continue making forward progress. Just so long as it remained difficult to either disrupt 1/3 of Bcash validators or acquire 51% of it, Bcash would continue functioning perfectly well (see: Jude C. Nelson [1]). At that point the rightful heir to the Bitcoin title would have to be determined socially. It could not be determined without top-down human intervention.
> But in the PoS corollary to Bitcoin v Bcash, coin-days staked would have no bearing on Bcash’s ability to continue making forward progress.
How wouldn't it? The ongoing coin-days staked in that fork specifically is what allows it to continue making forward progress. Just like how in a PoW fork, the ongoing consumption of energy in that specific fork is what determines the security of that fork.
The argument you link in that other thread is interesting but it doesn't appear to be exactly what you are talking about. They seem to be describing an attack where nodes are taken offline by the attacker.
> The ongoing coin-days staked in that fork specifically is what allows it to continue making forward progress.
Coin-days staked has no bearing on a pure PoS chain’s risk of being 51% attacked, nor does it have any bearing on the risk 1/3 or more of its validators get disrupted. Not so with PoW hashrate: enormous hashrate imbalances between forked PoW chains directly translate into decreased data immutability per the risk of deep chain reorgs.
Those risks are simply not present in the PoS corollary.
There is nothing wrong with it, the only trusted component is (obviously) in terms of the initial distribution of the staked coins, which is the central feature of proof of stake.
Whats the point? No one wants that beside that LN needs BTC on chain Tx which if you dont arbitrary define as final after some blocks makes it exactly the same - not final.
PoS/PoW is rather irrelevant. we already have solutions to make blocks/ledgers final its doesn't need PoW or PoS its just a properties that BTC doesn't have because it was designed without. There is no fundamental reason why it cant have it.