Proof of Stake Bitcoin?

[danBitcoin]

Initially I was hoping for a proof of stake Bitcoin as well. But then I realized that the best path for Bitcoin would be to move towards useful proof of stake, where the computations help the world somehow (like Gridcoin). Of course, they already help the world by confirming transactions, but more could be achieved.

I would say that Primecoin might be a better example of a useful secure PoW coin. You get big primes as a result, which is always useful in cryptography. Since prime numbers are used in public/private key cryptography, it would be kind of like it is feeding it self Who knows, maybe one day we figure out how to make a nice switch in Bitcoin's PoW algorithm, that might take some time tho.

Gridcoin is as useful. Check it out.

There's also Curecoin which supposedly does useful computations.

[Katashi]

For the situation right now, i don't really think so i think that would really not fair specially for the new miners specially those not holder
Of bitcoins yet. It will be more favorable for the old time miners perhaps.

[d5000]

How will you buy PoS coins from an exchange when the network isn't producing blocks? In this case, there is no way for the network to recover barring a hard fork, which is very damaging for a currency which is supposed to be decentralised.

You are right that that is definitively a disadvantage of PoS. But as I said, I don't consider it fatal, because the attacks you have described are very unlikely to succeed - and in any case, a hard fork can correct it, so it's not necessarily the death of the currency. In the case of a well distributed and accepted PoS currency, such an hard fork would very probably succeed because of collective action taken by the stakers to protect their stake.

The (very low) risk of a temporary blockchain halt is one I would be willing to take as a compensation for the big disadvantage of PoW (very high costs because of the miners' energy consumption).

[monsterer2]

The (very low) risk of a temporary blockchain halt is one I would be willing to take as a compensation for the big disadvantage of PoW (very high costs because of the miners' energy consumption).

The high cost of mining would be better spent on something more useful than solving a hash puzzle, but one thing that high cost does give us is a very clear attack cost for producing blocks, and therefore a bound on transaction acceptability.

[Mushroomized]

The (very low) risk of a temporary blockchain halt is one I would be willing to take as a compensation for the big disadvantage of PoW (very high costs because of the miners' energy consumption).

The high cost of mining would be better spent on something more useful than solving a hash puzzle, but one thing that high cost does give us is a very clear attack cost for producing blocks, and therefore a bound on transaction acceptability.

semi off topic, but this is exactly the reason I'm excited for stuff like filecoin/siacoin. It'd be fun to see if improving storage technology was actually more profitable because of increase in potential rewards.
I like the idea of POS because it acts as an incentive to hold coins and earn a passive bit of income (kind of like saving with a bank)

[d5000]

The high cost of mining would be better spent on something more useful than solving a hash puzzle, but one thing that high cost does give us is a very clear attack cost for producing blocks, and therefore a bound on transaction acceptability.

D'accord here, that's also why I'm still supporting Bitcoin's current model and I would not support a change to PoS (or a similar system) in the current state. We still need research and experience with current PoS coins and simulations about attack costs (e.g. with Nem or Nxt - PPC does not count because of the centralized checkpointing) until a multi-billion dollar currency like Bitcoin could be changed to that system. But that does not mean, for me, that we should discard PoS.

[JTASSOCIATES]

So far so Good so I don't think it is not required to go for Proof of Stake Bitcoin. Still long run to observe about it and in future how it is going to be we cant expect. so Expect the un Expected.

[naira]

For the situation right now, i don't really think so i think that would really not fair specially for the new miners specially those not holder
Of bitcoins yet. It will be more favorable for the old time miners perhaps.

I still do not understand why you say It will be more favorable for the old time miners perhaps.
Please give a little explanation sir

[aleksej996]

How will you buy PoS coins from an exchange when the network isn't producing blocks? In this case, there is no way for the network to recover barring a hard fork, which is very damaging for a currency which is supposed to be decentralised.

You are right that that is definitively a disadvantage of PoS. But as I said, I don't consider it fatal, because the attacks you have described are very unlikely to succeed - and in any case, a hard fork can correct it, so it's not necessarily the death of the currency. In the case of a well distributed and accepted PoS currency, such an hard fork would very probably succeed because of collective action taken by the stakers to protect their stake.

The (very low) risk of a temporary blockchain halt is one I would be willing to take as a compensation for the big disadvantage of PoW (very high costs because of the miners' energy consumption).

Well distributed currency does not exist and probably can't exist. Over time, rich are getting richer. Someone who is good at making money will continue to make money and might even use already acquired money to earn even more.

[allthebitandbobs]

I also think Bitcoin will not take the route to proof of stake. It works well in Proof of Work when it comes to being decentralized.   

I wouldn't called super mining warehouses  in china decentralize 

[xFiber]

The (very low) risk of a temporary blockchain halt is one I would be willing to take as a compensation for the big disadvantage of PoW (very high costs because of the miners' energy consumption).

The high cost of mining would be better spent on something more useful than solving a hash puzzle, but one thing that high cost does give us is a very clear attack cost for producing blocks, and therefore a bound on transaction acceptability.

semi off topic, but this is exactly the reason I'm excited for stuff like filecoin/siacoin. It'd be fun to see if improving storage technology was actually more profitable because of increase in potential rewards.
I like the idea of POS because it acts as an incentive to hold coins and earn a passive bit of income (kind of like saving with a bank)

Indeed that's why I bought some sia down the road. Mostly for the long term as well. PoS is also more accessible to the big public. You don't need to purchase expensive mining equipment nor pay high electricity bills. It's comparable to interest on a savings account indeed.

[d5000]

Well distributed currency does not exist and probably can't exist. Over time, rich are getting richer. Someone who is good at making money will continue to make money and might even use already acquired money to earn even more.

"Well distributed" does not necessarily mean "equally distributed". Whales are not automatically bad for a PoS currency. A PoS currency with, let's say, less than 50 whales that control 51% of the currency will be relatively weak because from these whales some could conspire and attack the currency.

But also a totally equally PoS currency where all participants have low amounts would be relatively weak because these participants could be vulnerable to the "bribing attack". The more people that really have a stake (=they would lose significant wealth if the currency dies or loses much value), the better for PoS currencies.

[aleksej996]

There is no telling on how centralized currency can or has to get over time. We can try and speculate that at no point there will be less then 50 people who control half of the coins, but I am pretty sure that richest top 50 have more then trillion dollars.

You can add more tricks to it with the banks and hedge funds where few control money that isn't theirs and you can have quite the pickle.

PoW is the safest way to have the confirmations, there will be same problems with the rich and powerful, but you don't have a closed club of the people with all the power, at least in PoW if you get the money or people pool the money together later, you can have the current powerful people broth down. In PoS it is a done deal, those few are safe for ever and if they fall the currency has to fall with them. People wouldn't won't to end Bitcoins's life, because few of the powerful are messing with them now and then. Revolutions would be more costly.

[d5000]

There is no difference between PoW and PoS with respect to the power of "the super-wealthy". Wealthy people that want power over the currency, in PoW can just buy hashrate and they will get it back and even probably profit from it. So they can increase their holdings slowly, just like in PoS. And if they want to attack the currency, they can do it, too - they need about 2-5% of the currency supply for 51% it for a long time, just as much as for many dangerous attacks in PoS.

The only difference with respect of the power balance - clearly an advantage - is that in PoW currencies you have a technically determined possibility for new people to enter (a person from outside the system can buy hashrate with fiat and get coins), while in PoS currencies the ease to enter the system depends exclusively on the market situation and so on social conditions. That's why I prefer combined systems (e.g. PoW/PoS like in Peercoin or Decred) to pure PoS currencies because it leads probably to a fairer distribution - with the cost of an more inflationary currency, but that should also incentive usage and dis-incentive too much "hodling".

[monsterer2]

There is no difference between PoW and PoS with respect to the power of "the super-wealthy". Wealthy people that want power over the currency, in PoW can just buy hashrate and they will get it back and even probably profit from it.

Actually, there is a difference: hash rate is more scarce than money. You can't buy 51% of hashing power.

[aleksej996]

There is no difference between PoW and PoS with respect to the power of "the super-wealthy". Wealthy people that want power over the currency, in PoW can just buy hashrate and they will get it back and even probably profit from it.

Actually, there is a difference: hash rate is more scarce than money. You can't buy 51% of hashing power.

Sure you can, you can buy almost anything with money.

But PoS is still less secure, because for PoW you need 51% right now and for PoS you need 51% at any point in time. There is simply a bigger attack surface. There is noting that PoS will save you from compared to PoW except the electricity, you can always lunch more attacks on PoS then PoW.

PoW is real, it is about a race, race in power, hashpower, but PoS is about who was a bigger part of it, ever. People always talk about how they owned something before it was popular, before everyone else came, here is where that is a problem. If you ever find people who once had a large portion of the currency, but since lost their power, you could probably get them together to take it back. If you have early adopters that don't like how the currency is going, then they have a good excuse to take the power back.

Ease of getting in the system is a good thing. It allows for progress, it insures decentralization and therefor security. PoS has fewer points of failure and more ways it can go wrong.

[d5000]

Actually, there is a difference: hash rate is more scarce than money. You can't buy 51% of hashing power.

If there is scarcity of mining hardware, that should be a temporary situation because of the current bull market. I don't know exactly how much it would cost to an attacker to fabricate mining hardware on his own (without having to wait for his [e.g.] Bitmain miners), but 2 billion $ (less than 3% of the Bitcoin supply according to "market capitalization") should be enough.

But PoS is still less secure, because for PoW you need 51% right now and for PoS you need 51% at any point in time. There is simply a bigger attack surface.

Yes, pure PoS currencies need restrictions on chain reorganizations because of that "long range attack" problem, even if practical long range attacks are difficult to perform (the "bribing attack" is well known, but in a mature currency should be impossible to perform, and the "buying old keys" attack would need an extremely long chain reorganization). There are however relatively elegant solutions for this, like Vitalik Buterin's "exponential subjective scoring". But even a simple rule ("don't reorg for more than 720 blocks") like in Nxt does the trick.

Ease of getting in the system is a good thing. It allows for progress, it insures decentralization and therefor security. PoS has fewer points of failure and more ways it can go wrong.

That relates to what I already said before: a currency without a (liquid) market is pointless. Thus, if a currency want to be successful, it must be easy to get "into" and "out of" it (buying and selling currency, or even more important buying and selling goods and services for that currency) - otherwise it will be a failure as a currency and only a speculative asset. That applies to PoS currencies, too. A "purely speculative" PoS currency (like almost all of current "altcoins") does indeed have the weaknesses you say, here I agree. But a coin that has real usage as a currency, does not.

[aleksej996]

Interesting idea about limiting chain reorganizations. I wonder how that would work. New nodes can't really know how many blocks are there and how much the reorganization is happening, then again I am not sure how you would make sure that blocks are created periodically. It is a weird idea that PoS thing, there is noting real that it binds to. It seems to me that if you want to be secure in PoS your node needs to be online all the time, you can't miss something, otherwise you are in trouble. Bitcoin isn't really so virtual and imaginary as some people say, it has some actual work placed behind it and scarcity of it enables it's value. In PoS you can create the whole 100 year history in just one second and two disagreeing blockchains would seem equally valid for a new node. PoS seems to me like a very risky idea, it should definitely be more tested before it would be implemented in the biggest cryptocurrency.

I didn't really refer to the ease of starting to use cryptocurrency, everything should be as easy to start to use as it can be. I was talking about the ease of getting power in the network. There shouldn't be any restrictions on your power in the network based on your time of adoption. Some people are simply young, some businesses are young, yet they are the ones that often bring true progress, a new idea that improves the old. Only to the new set of eyes you can objectively see the benefits and costs of both new and old system, because for a new person in the field, they are only evaluated by their characteristics and not by their age.

[d5000]

Interesting idea about limiting chain reorganizations. I wonder how that would work. New nodes can't really know how many blocks are there and how much the reorganization is happening, then again I am not sure how you would make sure that blocks are created periodically.

That is not a big problem - just look at the Nxt code how it's done. Chain reorganizations occur when there are two parallel chains, you are on "chain A" and suddenly your client detects a "chain B" with a higher "score" (in many PoS currencies that value is called "chain trust"). If the client comes into this situation, he simply must look if the last block that have both chains in common is more than e.g. 720 blocks "away" in the past. If yes, then it won't reorganize. The client will stay on the fork.

Now that could be undesirable, because a fork that normally would get "orphaned" could persist a long time because clients won't reorg. That is also why some dub the "reorg prohibition" a "dirty hack". But the answer to that is that such long forks normally only occur when someone is trying to attack. That's why "Economic Clustering" is used: This feature allows you to look fast if you are on the same chain than other nodes, for example, the exchange you use, or your friends. If nobody uses your fork, you cannot use your money on it. You would then abandon the fork on your own and start syncing the blockchain again.

It seems to me that if you want to be secure in PoS your node needs to be online all the time, you can't miss something, otherwise you are in trouble.

You are not necessarily in trouble, but you are vulnerable in this situation if you don't look on which other chain the other known nodes (exchanges, service providers) are. That is the main weakness of PoS. The well known blog post from Vitalik Buterin I already linked above explains it well.

In PoS you can create the whole 100 year history in just one second and two disagreeing blockchains would seem equally valid for a new node.

You would need a pretty big supercomputer to create a "100 year history in one second", but I get your point.

The "equally valid" does only hold true if both blockchains have exactly the same "score" which is very unlikely. Like in PoW, the "longest chain" wins - but in PoS, an attacker can re-create a "longest chain" with the well-known nothing-at-stake attacks, however, as already said, that's not trivial because he must obey the blockchain rules (he cannot create "stake" out of thin air, as long as he doesn't re-create the genesis block).

PoS seems to me like a very risky idea, it should definitely be more tested before it would be implemented in the biggest cryptocurrency.

Here I agree, as I already said. There is more research needed before implementing it in Bitcoin. I would also first implement a hybrid PoW/PoS version.

I didn't really refer to the ease of starting to use cryptocurrency, everything should be as easy to start to use as it can be. I was talking about the ease of getting power in the network. There shouldn't be any restrictions on your power in the network based on your time of adoption.

With the "reorg-prohibition" earlier described, "young" nodes have the same power than "old" nodes with the same stake.

[ashaksagnis]

i dont believe that btc will move to Proof of stake. Hard to believe.