Re: Ethereum could afford a 51% attack on Bitcoin, and profit greatly from it
now lets again ask you to do the math using jsut a small headstart
a 51% of honest network(2% advantage) is not enough hashpower to race against the honest network that is minimum 6confirm ahead
work out using math how many blocks it would take before the dishonest network can overtake the honest network
hint if just 6 confirm lead. the dishonest network with a 10% advantage(55% network) would need atleast ~44 blocks just to re-org a block that was initially just 6 blocks behind honest pools when the attack was initiated* and would need over 55 to be then 1 block ahead of the honest pools
* this is just a 6 block re-wind/re-org timeframe with a 10% lead(55% of network)
the more blocks a malicious pool need to go back. the more speed blocks it would require to build on from its edited block to then catch up
so if the service had a next day-72 hour goods/fiat delivery time.. the networks catchup time would be multiple factors longer to catch up
what you also find out is during those missing time blocks of dishonest catch-up time. there may be some miners working on that dishonest pool seeing that although it aided in building XX+ blocks for its pool for the pool manager to double spend pool managers funds. the miners are not seeing their attempted blocks ID and previous block ID visibly on the honest network YET, thus think they are running on some altcoin, so they would want to protect their investment, would jump to a honest pool whos blocks are visible
again the dishonest pool wont show results instantly. but would take time to get ahead of honest network to have results seen and the more blocks it has to go back the longer it takes to catch up to show results
run the math
a 51% of honest network(2% advantage) is not enough hashpower to race against the honest network that is minimum 6confirm ahead
work out using math how many blocks it would take before the dishonest network can overtake the honest network
hint if just 6 confirm lead. the dishonest network with a 10% advantage(55% network) would need atleast ~44 blocks just to re-org a block that was initially just 6 blocks behind honest pools when the attack was initiated* and would need over 55 to be then 1 block ahead of the honest pools
* this is just a 6 block re-wind/re-org timeframe with a 10% lead(55% of network)
the more blocks a malicious pool need to go back. the more speed blocks it would require to build on from its edited block to then catch up
so if the service had a next day-72 hour goods/fiat delivery time.. the networks catchup time would be multiple factors longer to catch up
what you also find out is during those missing time blocks of dishonest catch-up time. there may be some miners working on that dishonest pool seeing that although it aided in building XX+ blocks for its pool for the pool manager to double spend pool managers funds. the miners are not seeing their attempted blocks ID and previous block ID visibly on the honest network YET, thus think they are running on some altcoin, so they would want to protect their investment, would jump to a honest pool whos blocks are visible
again the dishonest pool wont show results instantly. but would take time to get ahead of honest network to have results seen and the more blocks it has to go back the longer it takes to catch up to show results
run the math
With 55% of the hash power, it will take, let's do some math: 55% × (6 blocks/hour) × t > 45% × (6 blocks/hour) × t + 6 blocks <=> t × (6 blocks/hour) × (55% - 45%) > 6 blocks <=> t > 6 blocks / (6 blocks/hour × 10%) = 10 hours.
In an earlier reply, you agreed that a 51% attack from Ethereum could last for several months in principle. (And in fact, if they go absolutely all in on the attack, then it could even be many years, at least in theory, as mentioned in my preprint.)
when doing an attack to re-org the blockchain to double spend your funds. each attempt is not going to happen in minutes. i was explaining that you first need to spend the funds and get goods or things of value in another form to then want to reset the network and remove the transactions existance to then spend it again. this will take not minutes but hours.
like i said if you want to attack the network to get double spend value of any significance services already delay things like deposits and withdrawals via things like X confirm wait or 72hour for bank withdrawals or 1 day to deliver packages. so you have to wait more then 6 blocks before resetting the tx/block
i used a 6 block min as a minimum for simple math.
but if you wanted to sell coin for fiat where its $1m involved you would have to wait 72 hours (432 blocks) and then go back 432 blocks and start from that point and then move forward.. which to then move forward and catch up would be like a 432*9 factor(3888)
by which time those participating in mining these unseen 3887 blocks before they match the honest network. those participating wont see those blocks on the network and would be more then likely prefer to jump away from the malicious pool because for 3887 blocks unseen also means not getting any rewards and also the honest network can still beat the dishonest network where the honest network may not get ahead for many other mitigating reasons.
yes the malicious pool after like 4000 blocks can then do it again. and for months respend a respend of a respend by keep repeating it for years. but again those participating unless they are seeing profits can simply jump to a honest pool in SECONDS
so while you think its a guarantee that a malicious pool with have endless power more then honest pools. what you dont realise is when the dishonest group are persuaded in the dishonest task to raid their eth stake, and buy bitcoin hardware, are more so pursuaded once invested in bitcoin to become honest, due to the lack of ongoing sat rewards per block because they are only getting possible returns of investment rarely and only if the malicious pool achieves the goal
a malicious pool wont reset the network transactions just to respend a coffee cup amount when it involves the risks of the honest network doing counter activities and also where it costs hundreds of thousands per block to do an attack which over 50-4000 blocks adds up to alot that the malicious pool would have needed to initially spend and receive goods from before trying to reset to then spend again to break even per attempt
so unless they are initially buying lambo's/mansions and ensuring the car/house is registered.. or they get $Xm's fiat in bank accounts that cant be cancelled/refunded/returned.. its not worth doing a double spend attack as its not as cheap as you think per attack
..
as for doing it to just win every block or every 2nd block to then spend the block rewards. again if you want to crash the market as a pool manager, you will find your asic workers you incited to be on your pool may want to get ROI on their hardware and instead want to save the network by jumping to honest pools now they are invested in bitcoin hardware and also help the market
..
also you lastly say white wash coins by moving them to different wallets(facepalm)
if you are re-orging blocks then any attempt to move funds gets undone when you the reset the blocks
you cant just hoard coins and delete transactions because the transactions is where the coins are.. they are not stored separately in wallets
your wallet does not store coins... your wallet just stores the signing key
if your resetting the transactions your resetting which addresses have the coins