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Comment by EGreg | Hacker News Reader

My favorite part about the blockchain is that it is a standard building block for decentralized byzantine consensus. Throw Ripple's XRP Consensus algorithm at 50-100 nodes and you know that 30% or more would have to be compromised to break the guarantees.

That's really cool because I can code the rest of the interface (front end etc.) with sloppy security and then ACTUALLY BOLT ON a secure layer with guarantees at the end.

Makes development much more streamlined. As the author of a huge codebase (https://qbix.com/platform) I worry that there are lots of security holes. With such a large attack surface, most new open source projects are swiss cheese, like early Wordpress (which is still full of holes from plugins).

Here, we just build our MODEL layer with a blockchain and KNOW the rules are going to be enforced.

Combine that with IPFS and a token and suddenly you don't have to pay for hosting to scale to billions of people. It's nice.

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Ripple is not trustless, so the blockchain part of it is moot. Since you have to trust Ripple (because they have full control), you might as well let them store the blockchain data on their own centrally controlled database.

What are you talking about? What exactly can Ripple do on its own network that you have to trust t not to do?

And anyway it's open source software! Why don't you go download the XRP consensus protocol from their github repo and try it. Ripple's servers won't even be part of the network.

If you want to be part of the Ripple network you have to trust Ripple's set of trusted validators. MySQL is open source, but that doesn't make a given MySQL server decentralized. Ripple in this case is that MySQL server.

If you want to be part of the Bitcoin network, you have to trust Bitcoin's miner du jour (actually du 10 minute).

What is there to trust? That they'll take your transaction? About the only thing they can do is refuse to include it in a block. Not much to trust really.

You don't have to trust anyone. You have to only trust that over 50% of mining power is motivated by cryptoeconomic incentives, which is a much more reliable assumption than assuming someone is altruistic or a good actor.

The fact that miners do not need to be known and trusted third parties means that there is great difficulty for any network adversary to identify enough miners to make an attack effective, and that even they were able to identify pools controlling >50% mining power, they would have great difficulty sustaining this attack as the network reacts by switching to new pools.

These facts in turn make it unlikely that a network adversary would

1. target miners in an attack as a means of controlling/obstructing the network

2. succeed in causing long lasting harm to the network in the event that they attempted such an attack.

Ripple's set of known and trusted validators can very easily be stopped and controlled by any reasonably powerful set of state level adversaries, and are themselves in a position to extract rent from the network due to the potential for such a group of known parties to collude, and the coordination problem that users of the network would have in hard forking away from such a colluding set of validators.

You have to only trust that over 50% of mining power is motivated by cryptoeconomic incentives, which is a much more reliable assumption than assuming someone is altruistic or a good actor.

That's still a lot to trust. How do I know someone isn't just gonna go crazy? How do I know someone isn't shorting bitcoin? That's rational.

Someone could short Bitcoin Cash and then mine in secret using Bitcoin ASICs and make a fortune screwing the whole Bitcoin Cash chain with their superior power. Proof of work sucks!

>>That's still a lot to trust. How do I know someone isn't just gonna go crazy?

It's not though because it takes a lot more than one individual to go crazy. It takes a huge number of people, who have a huge amount invested in the platform, to simultaneously go crazy and burn their hundreds of millions of dollars worth of their own assets down. People who own that much are generally mentally stable and focused individuals, and the idea that such a huge portion would spontaneously go crazy at the same time is extremely farfetched.

Relying on cryptoeconomic incentives is a much safer bet than trusting that a handful of trusted third parties won't be bent to the will of some political elite who pass a law, or won't collude to raise fees once they have attained a significant network effect and customer lock-in.

That same logic can and does apply to Bitcoin. The governments can seize or buy many ASICs and mine in secret to destroy trust in Bitcoin's longest chain.

The mining has ALREADY been centralized in a small number of mining pools. They become a cartel that charges high fees, no collusion needed. You have only one miner every 10 mins, and it has to take every transaction made in the whole world. You call that a good scalable design. Not to mention they can just be DDOSed.

But anyway tell me again why it's not rational behavior for someone to mine Bitcoin Cash in secret and then unleash their far longer chain, after shorting Bitcoin Cash on the exchanges? Why is Bitcoin Cash even secure at all?

1. Not all cryptocurrencies have ASIC mining. Ethereum has GPU mining. If a government attempted to attack Ethereum with GPUs that it bought, the public would likely react by turning their own GPUs toward Ethereum to protect it against the attack.

2. No one said that proof of work based cryptocurrencies can't be attacked. Obviously there's no such thing as an invincible protocl. The point is that it is much more costly/difficult to stop a proof of work based cryptocurrency than one that depends entirely on a small set of known and trusted third parties.

>>The mining has ALREADY been centralized in a small number of mining pools.

Already been addressed in my previous comment.

>>But anyway tell me again why it's not rational behavior for someone to mine Bitcoin Cash in secret and then unleash their far longer chain, after shorting Bitcoin Cash on the exchanges?

It would be much riskier than simply mining honestly. If they short it and their attack fails, they would lose a huge amount of money.

It's nice in an utopian kind of way, but it's actually less efficient - i.e. more costly overall. So you're talking Facebook paying for their hosting by showing ads vs you trying to charge customers real money or slow down their computers. I have a guess which one is going to prevail.

Hmm how do you figure?

Having people host with several nodes running a consensus algorithm is worse than trusting all your data to one actor in "the cloud"?

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