Energy Problem?


As a crypto enthusiast, I'm really excited to see what Zcash has to offer!

That said, is Zcash planning on working on Bitcoin's energy problem?


The exact scheme of proof-of-work we will use is unknown right now, but it will likely be memory-hard. I'm not sure we will factor in the environmental cost when deciding what scheme to use, though I am a fan of proof-of-stake.


Proof of stake ok but you need some coin to begin with then cpu must be a good choice to let any people without knowledge or specific hardware to mine it.


Maintaining a decentralised ledger is necessarily inefficient compared to a centralised equivalent. The more people that participate and make the network less susceptible to attack, the more energy is spent. However, making a problem arbitrarily difficult in order to prevent (in bitcoin's case) a peta hash network from doing it's job too well (consistently finding blocks in less than 10 minutes) is only one solution to the problem - there could be other solutions...

btw Ethereum was the first place I read about a memory hard proof of work scheme but apparently that was dropped. Can anyone confirm this?


I claim i am expert on this issue and that Zerocoin could use my expertise. The following thread I launched is my evidence:


I was designing memory hard hash variants in 2013 and even was talking to Charles (one of Ethereum founders) about Vitalik's PoW algorithm before Ethereum was created (when Charles was trying to organize the creation of Ethereum). And I had revealed to him the key flaw which ended up being admitted/realized later by Vitalik.

I have some recent comments about equalitarian PoW hash designs:


Even with a memory-hard puzzle, the puzzle is made arbitrarily difficult based on the amount of competitive participation. Memory-hard puzzles could shift the cost from energy to hardware, but the net effect on the environment should be the same if the participation is the same.


Proof of Stake requires a huge amount of engineering to approach the security of Proof of Work without actually getting there.
I think it would be unfortunate to address Bitcoin's fungibility issues while at the same time adopting PoS which would be a regression from the ideal of decentralized consensus.

You'd either have to merge mine or look at alternative PoW algorithms. It's pretty easy to just break the current algorithm to make current ASIC's not work, or you could do something different like the Cuckoo Cycle.


If all things are equal, it would be great if was as energy efficient as possible. However, the alleged "energy problem" should be a low priority issue and no compromises should be made to address it. Furthermore, while it's not outside the realm of possibility that we could face a (short-term) energy "crisis", over the long-term there will be exponentially more efficient forms of energy available, so let's not focus on what's essentially a non-issue.


I have roughly sketched a proposal which I am thinking will ameliorate the energy problem, remove the selfish mining attack (because mining becomes unprofitable), fix the block chain scaling, and Tragedy of the Commons around verification asymmetry for PoW (which is Ethereum's insoluble dilemma). It is in the thread I provided a link to previously, but I will point you to a more specific post that gets more direct to the economic math point (though one would still need to read the context of prior and subsequent posts of the thread):

However, this design may not work for Zcash, because Zcash has higher verification costs (but that is not a problem if the verification cost is still insignificant relative to the typical transaction values) and because the rate of transactions might be much more infrequent than the microtransactions market I was designing for (however if Zcash can be widely used then transaction rate may be sufficient and also the PoW share submitted with each transaction can be much higher than in my design because I assume anonymous transactions can be for much higher minimum values).

There may or may not be another hindrance with the fact that Zcash's block chain is afaik monolithic and amorphous, but I haven't thought through that issue yet.

Afair (and I don't have time to re-read it given all I have learned since I first read it) that paper did not articulate the most unarguable and salient reasons that PoS is inferior. I think we furthered the understanding in my linked thread. Also I wrote something about this in one of Vitalik's threads: