#raioninfluencer BlockTrain: “Blockchain can be hacked — The 51% Attack”

Before we understand about 51% attack, let’s understand some important terms:

• Hash Rate : Hashing is solving a mathematical problem of finding a valid hash to mine a block. Hash Rate is the number of hashes generated/calculated per second during a transaction throughout the network. Hash rate is a metrics of how secure a blockchain is, higher the hash rate of a blockchain more secure it is as many miners are competing to mine a block so the larger a blockchain network grows, stronger & more secure the network becomes. That’s why Bitcoin and Ethereum are the most secure blockchain till date.
• Hash Power : is the power that a node uses to run & solve different hashing algorithm.

Now, let’s understand what is a 51% attack:

➟ As we know a blockchain uses distributed mechanism of verification where all node should agree on the current state of the chain.

➟ When a group of miners control 51% of the mining nodes that controls the 51% of the hash rate of the network, they can deny new transactions or even reverse an ongoing transaction, even though changing the data in the previous block would not be possible. They control what will be next state of the blockchain and make the other nodes agree to that state as they have the majority stake.

➟It is easier to manipulate 51 out of 100 nodes rather than 5100 out of 10000, 51k out of 100k that’s why the larger a blockchain get’s more secure it becomes. It’s nearly impossible to attack big networks like Bitcoin and Ethereum.

➟ Controlling so many nodes at once is very expensive as the hacker will have to incur the mining cost to control 51% hash rate of the network.