How much would a 51% attack on Bitcoin cost?
After a 51% attack on the Bitcoin network, the network would have a hard time recovering.
After a 51% attack on the Bitcoin network, the network would have a hard time recovering. The blockchain is protected by hundreds of miners and verified by thousands of node operators and has been running continuously since launch. So far the proof-of-work blockchain has not been hacked.
A report from Kraken dives into the different consensus mechanisms. The data for the first time make clear what specific conditions would be needed to carry out a 51% attack on Bitcoin.
Conditions for a Bitcoin attack
Kraken's figures quickly make clear that anyone trying to hack Bitcoin needs money. Just the 216 million ASIC mining devices would cost almost nine billion dollars. Electricity costs, at nearly $20 million per day, would also be a heavy hit.
For comparison: hacking the Bitcoin fork Bitcoin Cash (BCH) seems much easier. Bitcoin Gold (BTG) — also a fork of the original BTC blockchain — has seen two such attacks. In 2018, a total of 388,000 coins disappeared after the 51% attack. Two years later another attack followed. Here, only $72,000 were stolen.
An attack on Bitcoin is thus far from likely. The cost-benefit would simply be too small. The miners, together with the node operators, form a solid base for this. In the future, the Bitcoin industry and the recent uptick in institutional interest could further contribute to network security. Recently, the world's largest asset manager, BlackRock, launched a private bitcoin trust.
