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The problem is how to achieve agreement (“consensus”) on the truth when at least one person is actively lying and trying to disrupt the truth. In the context of
by seibelj 8y ago
The problem is how to achieve agreement (“consensus”) on the truth when at least one person is actively lying and trying to disrupt the truth. In the context of digital money, it’s how you prevent the same coin being spent twice when manipulating digital information is easy.
A related problem is a Sybil attack, where a decentralized peer-to-peer system that is truly open makes it easy to generate new identities and overwhelm the system, so simply relying on the majority of accounts to agree on truth can still be subverted by a motivated attacker.
Bitcoin was a novel solution to this problem by using “mining”, or raw computation power, as a mechanism for enforcing consensus. This made Sybil attacks worthless as the only thing that truly matters in Bitcoin is computation power, which is expensive, and an attacker would need 51% of the power to attack the network.
- Aeolun 8y agoWhich several actors have actually had over the course of bitcoins existence, as far as I’m aware.
- jlborxes 8y agoAt the moment, accumulating 51% of the Bitcoin network's hash rate is prohibitely expensive. An attacker would be better off just using that massive hash power to legitimately mine bitcoins. This is the game theory behind bitcoin mining. Having said that, smaller PoW coins have been recently hit by 51% attacks, as renting the needed hash power for them is cheaper than the profits from selling the double spent coins.
- arcticbull 8y agoNot too expensive if you're Beijing. 75% of hashpower is centralized within the PRC. All Beijing has to do is inform the miners they now do their bidding. This kind of thing happens all the time in the PRC. The 'community' lost this fight ages ago, at this point Bitcoin effectively operates at the pleasure of Beijing, and one day that may very well change.