111–120 of 289 posts
I think I would be satisfied with the distributed consensus model in these blockchain systems if someone could solve the non-repudiation problem. In many of these blockchain systems, the 51% attacks only applies to money in motion. I can't move all of your funds out of 'your account' unless I have stolen your wallet, and if I have stolen your wallet I don't need to change anything else about the network. I can just s…
This is inevitable. Ethereum Classic (ETC) isn't the only currency such attacks have been successful on. The site https://www.crypto51.app/ puts the cost of running a 51% attack on ETC at ~$5k per hour. The incentive for running these attacks for profit becomes higher as the market cap of these coins increases, making long-term 'investment' in these coins nonsensical.
How can there be coins with $5M+ market cap where the cost of a 51% attack is $3.00 ?? In an efficient market, thieves should just immediately attack that. Or is the benefit too low?
You also have to actually do the double spend transactions, and hope that the person that you are stealing money from doesn't do anything about it.
It is that step 2 that is actually much harder than a nieve attack might suggest.
This is inevitable. Ethereum Classic (ETC) isn't the only currency such attacks have been successful on. The site https://www.crypto51.app/ puts the cost of running a 51% attack on ETC at ~$5k per hour. The incentive for running these attacks for profit becomes higher as the market cap of these coins increases, making long-term 'investment' in these coins nonsensical.
Yet another reason why Proof of Stake is destined to outcompete Proof of Work. ;)
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No one uses it. So you attack it. Cool. You can't turn it into USD or anything else, so you just spend $30 for nothing.
But you still get the prestige of having taken down a coin.
"Prestige" is how people end up in jail, or otherwise...
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If you're not on the largest coin for any particular interchangeable hashing algorithm then you're susceptible to these attacks, as people from a larger coin could simply turn their hardware against you and take you out. That means: For SHA256^2-specific hardware, Bitcoin (the real one, not Cash, Gold, or SV), for scrypt, Litecoin, and for anything mined on GPUs, Ethereum (not Classic).
Would you mind elaborating on this for someone unfamiliar?
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How can there be coins with $5M+ market cap where the cost of a 51% attack is $3.00 ?? In an efficient market, thieves should just immediately attack that. Or is the benefit too low?
The only way to profit is to double-spend, so you'll have to buy or already own a substantial amount of those junk coins and then sell them. After you performed the attack, those coins that you now could theoretically sell again may be suspended from trading or should at least trade at a substantially lower price. Add in the opportunity cost of exercising such an attack and it's not clear that you could turn a profit…
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In this kind of blockchain network, the longest chain of blocks is considered to be the valid one. However, someone that has 51% of the hashing power (i.e. more hashing power than everyone else combined) can create a chain that grows faster than the chain used by everyone else. This means that they could tamper with their chain, potentially rewriting history on it, and because it is the longest chain, it will be acce…
Being only somewhat familiar, I wonder this: Why don't clients have a simple rule against accepting changes to history that are more than one or two blocks old?
It is a pretty interesting solution, that seems to work out OK.
For example, most Bitcoin cash clients don't accept reorgs longer than 10 blocks, as such a reorg is 100% an attack. This protects the network against large reorgs.
I think I would be satisfied with the distributed consensus model in these blockchain systems if someone could solve the non-repudiation problem. In many of these blockchain systems, the 51% attacks only applies to money in motion. I can't move all of your funds out of 'your account' unless I have stolen your wallet, and if I have stolen your wallet I don't need to change anything else about the network. I can just s…
Earlier quoted context omitted.
How can there be coins with $5M+ market cap where the cost of a 51% attack is $3.00 ?? In an efficient market, thieves should just immediately attack that. Or is the benefit too low?
Well, the reality is that "attacking" a coin is much more difficult than just spending 3$ on something. You also have to actually do the double spend transactions, and hope that the person that you are stealing money from doesn't do anything about it. It is that step 2 that is actually much harder than a nieve attack might suggest.
An update from eth classic amount linked in that thread: (not sure what they mean by selfish mining...) Regarding the recent mining events. We may have an idea of where the hashrate came from. ASIC manufacturer Linzhi confirmed testing of new 1,400/Mh ethash machines #projectLavaSnow - Most likely selfish mining (Not 51% attack) - Double spends not detected (Miner dumped bocks)