What if bitcoin network is hacked?

Will bitcoin fall victim to attack/hack?

 

It’s believed that if 50% of the entire network/bitcoin is controlled, the attack could be possible. Or let’s say 51% attack also known as “An attach on cryptocurrency blockchain by a group of miners who control more than 50% of the network’s mining hash rate”. Let’s’ look at the cost/implication of owning 51% of the network’s hash rate.

Owning 51% of the nodes on the network theoretically gives the controlling parties the power to alter the blockchain. In other words, the group of attackers owning 51% of the total hash rate will prevent the ‘honest’ miners/rigs from adding new blocks (or confirming new transactions). If 51% of the network is controlled, there may be the possibility of reversing the transactions that were completed, thus leading to the issue of ‘double-spending’.

As we know, the blockchain’s network reaches a majority consensus about the transactions through a validation process, and the blocks where the information is stored are sealed and link together via a cryptographic techniques. But to be precise, changing the historical blocks-transactions locked before the start of the attack would be extremely difficult even in the event of a 51% attack.

Reason 1. While the 51% attackers start reversing the transactions, imagine other ‘honest’ miners who keep on adding the valid transaction:(This is one of the reason why reversing or attacking the network is not at all possible.

Let’s take the cost implication into consideration. The most advanced ASIC miner such as Bitmain S19 XP Hydro costing more than $8400 has a hash rate of 257 TH/s. As of June 7, 2023 the top three mining pools
a. Foundry, USA has 106.16 EH/s i.e., 29.3% of the total bitcoin network hash rate.
b. Antpool has 90.28 EH/s i.e., 24.9% of the total hash rate
c. F2Pool has 45.98 EH/s i.e., 12.67 of the total hash rate.
Combining these three pools makes a total of 66.87% of the total hash rate i.e., 242.42 EH/s. Thus, to reach this hash rates, one would need 941,634 S19 XP Hydros costing close to $7.9 billion (excluding the cost to build the infrastructure, staff, electricity, etc.,).

Reason 2: Now who could be bold enough to invest $7.9 billion (excluding the cost to build the infrastructure, staff, electricity, etc.,) to attack the bitcoin network? This is really insane. ;-) And even if after investing this much and the attack fails. What’s next? (Remember ! The honest miners keep on adding the blocks to the main chain and the main chain would rather continue to grow bigger than the alternate chain).