Proof of stake

[Jet Cash]

I've had a lot of trouble in understanding the SegWit/blocksize controversy, and I have spent a lot of time reading about Bitcoin basics and development.. A couple of interesting topics that I discovered are side chains, and proof of stake. It seems that there is a small body of opinion that thinks proof of stake should be added as an alternative to proof of work. This seems like a brilliant addition to me. If it were to be used in conjunction with side chains, it would allow unbanked communities to develop their own alt coins, and peg their values to the value of Bitcoin. It would also help to contain the size of the blockchain, as all transactions within the community would be stored in the side chain, and demands on the main blockchain would be limited to increases or decreases in the base capital of the alt coin. It would also expand the investment potential of Bitcoin, as it would become the "gold" standard for these alt coins.

Have I understood these concepts correctly?

[Moloch]

In theory, people like proof of stake...

In practice, its quite vulnerable to attack.

With PoW, you need 51% of the network hashrate to perform 51% attacks... with PoS, you also need 51% of the network hashrate.  The difference is in how the hashrate is determined...  Your hashrate in a PoS network is proportional to the number of coins in your wallet multiplied by how long it has been since they last staked.  So, by taking your wallet offline for a few days, you multiply the hashrate... you can turn 1% of the coins into 10% of the hashrate (or more)... making it extremely vulnerable to 51% attacks like double-spend...

It is my understanding that no PoS coin has fully addressed this issue...

Also, every PoS coin I have looked at is a clone of peercoin, which was forked from bitcoin at v0.6.3, and has not kept up with the core.  It is missing every single feature that bitcoin has added/fixed/upgraded since 0.6.3 (4 years ago?)

[Jet Cash]

My understanding is that this would be an addition to the Bitcoin protocol, and would be an alternative to the proof of work, not a replacement. It would reduce the demands on the blockchain once the PoS was confirmed. It would be a long term deposit if it was used to backup value of an alt coin on a Bitcoin sidechain. Would there be any hashrate requirement if the PoS was an alternative to PoW. ie. no work needs to be done to confirm it?

[Bungeebones]

I've not grasped any benefit to POS coins either but sidechains are a different matter. I've got a sidechain/token experiment going on at Bungeebones.com and am leaning towards sidechains could really shine where they are backed by a commodity or service. In my case, they are backed by web advertising. Every Bitcoin coming into the system causes the creation of a token (used to actually buy advertising) but each token is redeemable for Bitcoin. Within the eco-system the token is used but as soon as they are redeemed for Bitcoin they are destroyed. In many ways, the token is an IOU Bitcoin. It would be counterproductive and destructive for me to create IOU Bitcoin. Similarly, if participants want Bitcoin they want to redeem them as soon as possible and, conversely, only leave them in the system if they want to buy the product. The goal is to minimize the amount in the system that is owed and only keep enough "cash in the till" to accomplish the foreseeable transactions.

[Jet Cash]

That's a nice concept, but it looks as if it is designed to earn Bitcoins from outside the chain. Obviously this is a great use of side chains. My thought on PoS was based more on using existing Bitcoins to give value to the altcoin in the sidechain. The altcoins would be used for local trading. Of course they could be sold for Bitcoin outside the altchain, but this would not add value to the chain deposit. To increase the number of altcoins, extra Bitcoins would have to be stored in the "vault" with an associated PoS. Obviously this is no longer a distributed control system, but would have to be administered by a central authority (just for the altcoins), but this may not be a disadvantage for an institution, or a community. Any increase in the value of Bitcoin, would increase the value of the Altcoin in direct proportion, so it could be used as a tradeable investment holding.

[Brangdon]

It is my understanding that no PoS coin has fully addressed this issue...

I'm surprised you think that. Nxt is an example of a PoS coin that does not use coin age, and does not have the problem you mention. It's been running successfully for over 2 years, and is not a clone of Peercoin. Qora is another. There are more.

[letsplayagame]

It is my understanding that no PoS coin has fully addressed this issue...

I'm surprised you think that. Nxt is an example of a PoS coin that does not use coin age, and does not have the problem you mention. It's been running successfully for over 2 years, and is not a clone of Peercoin. Qora is another. There are more.

There are other PoS attack vectors. Just because someone has not successfully made an attack yet does not mean it cannot happen in the future.

[Brangdon]

It is my understanding that no PoS coin has fully addressed this issue...

I'm surprised you think that. Nxt is an example of a PoS coin that does not use coin age, and does not have the problem you mention. It's been running successfully for over 2 years, and is not a clone of Peercoin. Qora is another. There are more.

There are other PoS attack vectors. Just because someone has not successfully made an attack yet does not mean it cannot happen in the future.

Sure. I'm not advocating PoS in Bitcoin, just correcting that specific piece of misinformation.