The news about 51% attack on bitcoin with US$760,000 was widely spread on the network, and some well-known currencies such as ETH, BCH and BSV had all become the targets. It seems that the cost of launching a 51% attack is far less than our imagination. Many “smart guys” quickly came up with the idea of launching a 51% attack on bitcoin to get profits in the futures market. Unfortunately, they are just daydreaming.
As the pioneer of bitcoin, POW (Proof of Work) is widely regarded as a solution integrating security, decentralization and fairness in the consensus mechanism. The stable operation of bitcoin network for nearly decade is the best example.
The only way against POW mechanism is the 51% attack —- when certain attacker controls more than 51% of all the hashrate, he can generate the longest chain singlehanded —- the attacker can make hard fork with double-spending attack anytime. It is easy to see that such an attack demands big price from the attacker, so it only theoretically exists on paper until May 2018.