[SC] Cryptocurrencies #573 $10K MET DE KERST

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Op vrijdag 3 november 2017 18:44 schreef fckdedeurkruk het volgende:

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Hmm interessant. Zou je iets duidelijk kunnen zijn hoe dit een 51% attack is? Of heb je misschien een artikel die je kunt linken?

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The plan by the SegWit2x developers is to execute the fork in such a way that the legacy chain does not survive. In their view, they are upgrading the network according to the definition of Bitcoin in the Bitcoin white paper, which consistently describes Bitcoin as being the longest chain and that being the longest is "proof that it came from the largest pool of CPU power." If all goes according to their plan, such a large amount of hash power will go to mining the 2x chain that the 1x chain will basically become dysfunctional -- blocks could take hours to get added to the chain, fees could become prohibitively high as people compete to get their transactions included in the next block, and because most parties require a transaction to be six blocks deep in the chain to consider it confirmed, confirmation times will become excessively long. Miners compete to get the new Bitcoins mined on the network and how easy it is to obtain that award is determined by something called the difficulty algorithm that adjusts every 2,016 blocks, which turns out to be every two weeks as long as a block is processed on average every 10 minutes. But if, say, 90% of miners are no longer mining on that chain, it will take 100 minutes to find a block, 10 hours to get a confirmation, and 140 days for the difficulty to readjust.

Additionally, the developers of the SegWit2x plan are not instituting a technical measure called replay protection that would entirely separate the transactions on the two blockchains. Without replay protection, if both chains survive, any transactions that occur on the 2x chain will also be replicated on the 1x chain and vice versa. However, this will cause more problems on the chain with less mining power because blocks will be mined more slowly. Let’s assume the chain with less mining power is the 1x chain. That means that if you are a 1x supporter and dump your 2x coins, you will also lose your 1x coins. (According to core developer Eric Lombrozo, some people plan to offer special services that enable people to separate their coins so they can transact in them without replaying the transaction on the other chain.) Belshe says they aren’t instituting replay protection because their intention is that there will only be one chain, not two, after the fork.

In general, a chain with little hash power will be vulnerable to attack. If only 5% of current hash power remains on that chain, then any miner with enough power can turn 5.1% of current hash power on to the first chain and double spend to their heart’s content in what's called a 51% attack.