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Miners Aren’t Friends

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Re: Miners Aren’t Friends

#71

Post by wk2jkhkjdfglsl »

AlwaysBCoding wrote: post #33
corford wrote: post #19

Earlier quoted context omitted.

I don't understand the economic argument for personal mining (I totally get it from a fun, geeky PoV if making money isn't the primary goal - it's how I got started in crypto). A GTX1070 costs about $800. At $4/day, it will take you 200 days to make back your principle (ignoring power costs, difficulty scores going up etc. - in reality it will obviously take you even longer to cover your costs). If you had put that s…

If you're buying stuff on darknet markets it's nice to be able to do it with freshly mined coins that don't have transaction histories associated with them.

This would only apply to solo-mined block rewards. If you use a mining pool, there is a coin trail through the pool. The pool likely has the IP address records of your miners and can link these to your payout transaction.

Mined coin is only just a little less traceable than exchange purchased coin.

Re: Miners Aren’t Friends

#72

Post by RoboTeddy »

konschubert wrote: post #59
RoboTeddy wrote: post #41

Earlier quoted context omitted.

Can imagine a protocol for generating randomness to some arbitrary security level (at the expense of locking up security deposits): (1) Anyone can decide to become a 'randomness provider' by putting up a large security depsoit (2) Every epoch (some number of blocks), each provider chooses a private random number and commits to it by publishing its hash (3) During the next epoch but, each provider publishes the random…

> If you're worried about bribing attacks over all providers, recognize that all we need is a single altruistic provider to keep the system safe. Altruistic behavior may be rare compared to selfish behavior, but I think we can usually rely on its nonzero presence. You also need to be sure that the others don't ignore the single altruistic source. In a byzantine system, you can't distinguish if somebody is offline or…

> You also need to be sure that the others don't ignore the single altruistic source.

Well sure, but the code people run listens to all the providers. Everyone is listened to automatically. That's part of the social consensus encoded in software. If you don't follow along, you end up on your own fork. That's how these systems work — e.g, you also need to make sure that people don't "ignore" the consequences of failed hash checks throughout a cryptocurrency codebase.

It would be quite possible to run your provider on a machine hidden somewhere, and inject your transactions to nodes at random points in the network. It'd be pretty tough to silence someone directly.

Miner censorship attacks, e.g. a 51% attack, are also possible (i.e., all miners, or a sufficient majority, refuse to mine your tx until the epoch ends). This kind of censorship threat is always present for all kinds of transactions; in theory they're particularly pernicious for protocols like this one that require a tx to be submitted by a deadline. But no one is claiming that these systems are completely invulnerable to a misbehaving majority of miners or validators.

Re: Miners Aren’t Friends

#73

Post by jancsika »

MrBingley wrote: post #66

Can someone explain to me how on earth Ethereum is still a thing? People have lost hundreds of millions of dollars in the Ethereum ecosystem, many due to basic flaws in the "Solidity" language. For example, last November $280 million was frozen in Parity wallets because function visibility defaults to external rather than internal (see the previous HN discussion here[0]). Just for fun, I was looking through the Secur…

Well, they start with an assumption that the halting problem is addressed simply by "running out of gas." I could easily see a dev assessing the infinite loop potential and glibly thinking, "well, that would just run out of gas, too."

That doesn't explain the lack of guarantee on "constant". What is the technical detail which prevents such a guarantee?

Re: Miners Aren’t Friends

#74

Post by RoboTeddy »

barbegal wrote: post #56
RoboTeddy wrote: post #46

Earlier quoted context omitted.

The system itself, e.g. the code of a smart contract. Example implementation: https://github.com/randao/randao

So the randomness providers secure the deposit of their own randomness. The circularity of the system means it won't work in practice. RANDAO is secured by the proof of work miners.

Actually, this kind of "snake eating its own tail" loop is exactly how cryptocurrencies operate. For example, proof of work blockchains secure themselves by creating mining incentives with money that has value because it is secure.

It works because the system can regress over time, e.g. value at t=n can be used to secure a greater amount of value at t=n+1. (Although value needn't be strictly increasing for system to operate; if value decreases, so do the security requirements)

Re: Miners Aren’t Friends

#75

Post by wk2jkhkjdfglsl »

CloudYeller wrote: post #52

Do these vulnerabilities affect BTC? Is there any unbiased source of security reports on all the various coins?

Not exactly because bitcoin only supports a few simple transaction types -- Pay to Public Key, Pay to Public Key Hash ('standard tx'), Pay to Script Hash, Pay to Public Key Witness Hash, Pay to Script Witness Hash.

These are only serial dependent -- ie: A pays B, B pays C. You cannot reorder and still remain valid.

The security of the standard tx is the strength of the public key hash function RIPEMD-160. The security of Pay to Script Hash is finding a valid SHA256 collision with OPCODES.

The witness variants are a new tx format that uses less space (aka segwit).

The attack is simply a Denial of service, an attacker can block a tx. So if A pays B was never included in a block, B could never pay C.

Re: Miners Aren’t Friends

#76

Post by corford »

ConnorLeet wrote: post #68
corford wrote: post #47

Earlier quoted context omitted.

I still don't get it :( That's 108 days before you _start_ to make a profit and future returns are guaranteed to diminish as difficulty goes up. Versus £5,200 capital to invest immediately in a basket of safe (as much as crypto currencies can be), liquid coins that will likely x3 to x8 over a 12 month period. To each their own I guess but it's not the bet for me.

If the whole crypto ecosystem crashes (unlikely in my opinion) graphics cards can be resold and recoup losses.

Not sure this holds either. With such a black swan event, there would be a glut of second hand graphics cards on ebay etc.

Seems safer to me (if you're worried about a huge crash) to leave your principle investment equivalent amount on a good exchange with fiat support (e.g. Bitstamp) setup a sensible stop loss order and then, as soon as you've x2 your original investment, pull your initial stake out and leave the rest in crypto (on a Nano Ledger S or similar).

Re: Miners Aren’t Friends

#77

Post by mhluongo »

barbegal wrote: post #62
mhluongo wrote: post #54

Earlier quoted context omitted.

Publicly verifiable randomness is possible without relying on astronomical events. Check out threshold relay by the Dfinity team (which we're porting to Ethereum), or RandHound and RandHerd [1]. 1 - https://eprint.iacr.org/2016/1067.pdf

That paper assumes that at most f out of at least 3f+1 participants are dishonest. In practice one can't make that assumption since sybil attacks are easy.

You can bootstrap a Sybil-resistant system using PoW or some other method. This is one building block.

Re: Miners Aren’t Friends

#78

Post by ve55 »

MrBingley wrote: post #66

Can someone explain to me how on earth Ethereum is still a thing? People have lost hundreds of millions of dollars in the Ethereum ecosystem, many due to basic flaws in the "Solidity" language. For example, last November $280 million was frozen in Parity wallets because function visibility defaults to external rather than internal (see the previous HN discussion here[0]). Just for fun, I was looking through the Secur…

Solidity has a lot of potential pitfalls that need to be avoided, just like similar languages. Some of these are due to poor or unintuitive language design, although a lot of improvements have been made over time. The wallet bug involving Parity's multisig wallets was due to an error that Parity made, even if it's an error that may have been easy to make, it should have been caught in testing or code reviews due to how critical that library was. As far as the loop goes, you cannot have a loop that runs forever due to gas limits involved in transactions (a contract can only execute so many opcodes before it hits the gas limit and execution halts, with state reverted back), so it isn't a potential issue that it would never terminate. With that said Solidity still has some pitfalls that should be fixed, and many of them already have been fixed. It's not perfect, but it's quite usable compared to other smart contract systems, few of which are even as developed.

Most of the largest headlines involving loss of funds in the Ethereum network have been due to programmer or user error. Keep in mind that Ethereum is still in its "experimental" phase - it isn't "supposed" to have billions of dollars put into it just yet, but the market doesn't care about this as long as the prices are going up. Ethereum could be much worse than it is, but that wouldn't mean its value would go to zero, or even do down. Plenty of top coins by market capitalization have been orders of magnitude worse, or just outright scams. Remember "The market can stay irrational for longer than you can remain solvent".

It's still a very new area of technology despite the amount of money that pours into it. There's innovation, but it can be difficult to see it in the midst of the hype.

Re: Miners Aren’t Friends

#79

Post by masklinn »

Bromskloss wrote: post #70
MrBingley wrote: post #66

Can someone explain to me how on earth Ethereum is still a thing? People have lost hundreds of millions of dollars in the Ethereum ecosystem, many due to basic flaws in the "Solidity" language. For example, last November $280 million was frozen in Parity wallets because function visibility defaults to external rather than internal (see the previous HN discussion here[0]). Just for fun, I was looking through the Secur…

Does Ethereum's existence hinge on Solidity? Isn't Solidity just a language that one can compile to the lower-level language actually built into Ethereum?

Solidity is the official language, part of the ethereum project, and pretty much all you get when you look for how to develop eth contracts, unless you specifically exclude mentions of solidity. Then you get Ivy (prototype & for bitcoin not eth) and Pyramid Scheme.

So I'd say yeah, technically not but practically it is.

Re: Miners Aren’t Friends

#80

Post by blunte »

Bromskloss wrote: post #70
MrBingley wrote: post #66

Can someone explain to me how on earth Ethereum is still a thing? People have lost hundreds of millions of dollars in the Ethereum ecosystem, many due to basic flaws in the "Solidity" language. For example, last November $280 million was frozen in Parity wallets because function visibility defaults to external rather than internal (see the previous HN discussion here[0]). Just for fun, I was looking through the Secur…

Does Ethereum's existence hinge on Solidity? Isn't Solidity just a language that one can compile to the lower-level language actually built into Ethereum?

The promise of Ethereum was to be a global, decentralize, virtual computer. Without smart contracts, it's just another electronic value exchange platform.
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