What is a 51% attack on a blockchain?

Blockchains are distributed ledgers that record every transaction made on a cryptocurrency's network. A 51% attack is an attack on a blockchain by a group of miners who control more than 50% of the network's mining hash rate.

How does a blockchain attack work?

People in control of such mining power can block new transactions from taking place or being confirmed. Attackers use 51% attacks to reverse transactions that have already taken place, in a blockchain, in what has come to be known as double spend.

How does a 51% attack work?

A 51% attack works by overruling an existing network to take over the set security protocols. These impacts may or may not be severe, but it all boils down to the power of attackers hold. So, the more percentage of hash power the attackers have, the easier it is to carry out the attack. Ultimately, the damages are more consequential.

How rare is a 51% attack on Bitcoin?

51% attacks on Bitcoin blockchain arerare because an attacker would need computing power or hashing power superseding that of millions of miners all over the world. To be able to initiate such an attack one would need to spend an enormous amount of money to acquire mining hardware capable of competing with the rest of the network.