How much would a 51 percent attack actually cost?

Attempting to hack BTC would result in financial ruin for the attacking entity. Protected by hundreds of miners and verified by thousands of node operators, the blockchain has been running continuously since it was launched. So far, the proof-of-work blockchain has not been hacked.

A report from Kraken goes into the different consensus mechanisms. The data clarifies for the first time which specific requirements are necessary in order to be able to carry out a 51 percent attack on BTC.

Conditions for a 51 percent attack

The numbers from Kraken quickly make it clear that anyone who wants to hack BTC needs money. The 216 million ASIC mining devices alone would cost almost nine billion US dollars. Electricity costs are also a heavy hit at nearly $20 million a day.

In comparison, hacking the BTC fork BTC Cash (BCH) seems to be a lot easier. BTC-Gold (BTG) – also a fork of the actual BTC blockchain – has already seen two such attacks. In 2018, a total of 388,000 coins disappeared after the 51 percent attack. Two years later another attack followed. Here, however, only 72,000 US dollars were stolen. You can find out more about BTC hard forks here.

An attack on BTC is therefore anything but likely. The cost-benefit effect would simply be too small. The miners, together with the node operators, form a solid foundation for this. In the future, the industry surrounding BTC and the recently increased interest from an institutional point of view could contribute even more to securing the network. Only recently, the world’s largest asset manager BlackRock launched a private BTC trust fund.

Methodology

The data refers to the ASIC model Bitmain Antiminer S 19, while the energy costs in the calculation are 0.1177 US dollars per kilowatt hour. This corresponds to the average electricity price for companies in the USA.