What is a 51% Attack?
A 51% attack is a security threat in blockchain technology, especially in decentralized networks such as Bitcoin. In a 51% attack, if a single entity or group gains control of over 50% of the network’s mining hash rate or computational power, they could potentially manipulate transactions. This could involve double-spending, blocking new transactions, or reversing transactions that were recently confirmed.
Such attacks are challenging and expensive to execute, especially on large and decentralized networks like Bitcoin. However, smaller blockchain networks with lower hash rates are more vulnerable, as achieving majority control is easier and requires less computational power.
In practical terms, a 51% attack undermines trust in the network, as it compromises the integrity of transaction records. For instance, if a miner successfully executes a 51% attack, they could create a transaction where they purchase goods, then reverse the transaction afterward to reclaim their funds—a form of double-spending.
While a 51% attack does not allow hackers to steal funds from other wallets directly or create new coins, it poses serious risks to the network’s security and reliability, affecting user confidence and potentially devaluing the currency.
