New numbers show just how much money it would take to launch 51 percent attacks on Bitcoin (BTC) and other proof-of-work (PoW) cryptocurrency networks.
PoW is a protocol used by many blockchains to keep networks secure and to validate transactions, preventing attacks by enabling a distributed consensus of trustless transactions.
A 51 percent attack happens when a single entity takes control of at least 51% of the network’s mining hashrate or computing power, enabling it to prevent confirmation of new transactions, halt payments among users, and even reverse completed transactions that will allow double-spending of a single coin.
Using price data from NiceHash, a marketplace for buying and selling hashing power, Crypto51 shows a dynamic list of how much an entity needs to spend to attack the Bitcoin network: $641,011 per hour, at time of writing.
The cost of taking over the Ethereum network is far less, at $84,307 per hour. The third most expensive network to attack is that of Ravencoin, with attacks costing $21,538 per hour. Dash, the ninth coin on the list, implemented an upgrade called ChainLocks last year, which reduces confirmation time in an effort to make it nearly impossible to execute such an attack.
Cost of 51 percent attacks per hour/# rank of cryptocurrency by market cap