What is 51% attack 🚨
51% attack is a vulnerability of the blockchain based on the PoW (Proof of Work) algorithm. Due to the vulnerability, hackers can control the confirmation of transactions and new blocks generation.
With 51% of the network's power, the hacker can:
- prevent other miners from finding new blocks;
- prevent transactions or blocks confirmation;
- grab block rewards and transaction fees.
The consequences can be more serious if hacker owns more than 51% of the network's power. However, it is almost impossible, since it requires more financial resources than some specific skills of the hacker.
That is why only small cryptocurrencies, which have little of their own computing power, are susceptible to such attacks. Bitcoin and popular altcoins are not threatened. But nevertheless, the possibility of an attack still extends to less powerful altcoins.