Nice work. Its really important to consider this for those buying/holding crypto currency. Consider all coins using the same function to be the same family and the one with the most work and power to be the most valid. So there are sha256 coins, scrypt coins, equihash coins, etc. In the case of sha256 the most immune to attack is bitcoin. Everything else is massively vulnerable. In the case of scrypt, it’s litecoin. Everything else you should not hold because it can be swamped by the hashing power mining litecoin atm. So on.
This is a little different from how people have been told to think about it before which is just focusing on the blockchain itself rather than the mining power behind any given variation/fork/whatever of block chain.
Ps. And that probably should be taken a step further. If you have families of coins that are all GPU mined, then you need to consider the tota GPUs mining them and the hashing power of those GPUs and the ability for them to switch functions. Now GPUs are a blip on ASICs so for the predominantly asic mined coins this doesn’t matter.
Exactly. This is also why I think the trend to be "ASIC-resistant" is misguided and should be considered harmful.
All GPU-mined coins (except the hashrate-dominant one: Ethereum) are massively vulnerable to majority attacks because of the huge pre-existing installed based of GPU miners.
As I said in https://news.ycombinator.com/item?id=17173774 the only solid defense is for each coin to implement an ASIC-friendly algorithm that is unique to this coin, so there is no risk of 51% attacks from a pre-existing installed based of miners.
I've yet to see anything other than PoW that's got all four;
* genuine decentralization
* reliably generates a concensus with global supermajority, little or no forking (objective chain selection)
* fault tolerant network, minimal fragility / auto recovering, can't be permanently crashed / hijacked
* requires no human intervention
Everything I've seen so far in terms of PoS violates at least one of the above.
Hashgraph doesn't deal with concensus (it offload that to other layers), Ripple doesn't really deal with decentralization, Algorand is fragile, most PoS require human intervention besides often having several other faults.
Also there's probably more criteria like these that matter.
"Genuine decentralization" / and "consensus" are not necessary to make a useful currency.
There's also massive cost and risk with the currencies that do implement those criteria.
We should all be open to different alternatives that WORK, and not reject them out of hand just because they're not implemented in such a way that they have attributes we LIKE.
Dropping global concensus means you're back to small regional currencies. With centralization you get things like Ripple. Both problematic / unstable in the long term.
> Consider all coins using the same function to be the same family and the one with the most work and power to be the most valid. So there are sha256 coins, scrypt coins, equihash coins, etc. In the case of sha256 the most immune to attack is bitcoin. Everything else is massively vulnerable.
This is a really good point, and part of what I am hoping people come to understand from this website. Ignoring the risk of renting power from NiceHash to launch an attack, large existing miners could easily switch to a smaller coin for a few hours to attack it, and typically it would be very profitable.
I wonder whether the indirect benefits of discouraging competing coins would outweigh the costs of loss of confidence in crypto currency is in general (and the computer cost).
Just want to note that there’s no risk in holding a token due to 51% attacks (except for the external issues such as loss of value and hard fork proposals). No one can spend your assets, it’s just another transaction may double spend (so you could lose incoming tokens).
This is a little different from how people have been told to think about it before which is just focusing on the blockchain itself rather than the mining power behind any given variation/fork/whatever of block chain.
Ps. And that probably should be taken a step further. If you have families of coins that are all GPU mined, then you need to consider the tota GPUs mining them and the hashing power of those GPUs and the ability for them to switch functions. Now GPUs are a blip on ASICs so for the predominantly asic mined coins this doesn’t matter.