$$BTC #Bitcoin is a decentralized #criptomoneda that works through a network of nodes that validate transactions and record them in a chain of blocks or blockchain. This technology guarantees the security, immutability and transparency of operations carried out with Bitcoin.

Still, there is a potential vulnerability that could compromise the integrity of the Bitcoin blockchain: the 51% attack. This type of attack occurs when an entity or a group of entities manages to control more than 50% of the computing power or hash rate of the network, allowing them to alter the blockchain consensus and perform malicious actions.

How does a 51% attack work?

Bitcoin uses a consensus mechanism called proof-of-work (PoW), which consists of nodes or miners having to solve complex mathematical problems to verify transactions and add them to the #blockchain The first miner to solve the problem receives a reward in the form of bitcoins and the rest of the nodes accept the block as valid.

If a miner or group of miners controls more than 50% of the network's hash rate, they can create a parallel chain or fork that competes with the original chain. By having more computing power, the attacker can make his chain longer and faster than the legitimate one, and eventually impose it as the real one.

This would allow the attacker to perform actions such as:

- Block or reverse other users' transactions, preventing them from receiving or sending bitcoins.

- Perform a double spend, that is, spend the same bitcoins two or more times, sending a transaction to the legitimate chain and then canceling it with another transaction to the fake chain.

- Censor or exclude other miners from the network, reducing competition and decentralization.

- Manipulate the mining difficulty level, making it easier or more difficult for other miners to obtain rewards.

These actions could have serious consequences for trust.