51% Attack

A 51% attack refers to a scenario in blockchain networks, particularly Bitcoin, where a single entity or a coordinated group gains control of more than half of the network’s total hash rate—the computational power used to validate transactions and secure the blockchain. With majority control, the attacker could potentially reverse recent transactions, enabling double-spending, or censor certain transactions from being processed. This undermines the fundamental trust and security model of decentralized cryptocurrencies.

Despite the theoretical risk, executing a 51% attack on the Bitcoin network is extremely difficult and costly. The sheer scale of Bitcoin’s mining power, combined with the vast energy consumption and sophisticated hardware required, makes acquiring majority control prohibitively expensive. Additionally, Bitcoin’s decentralized mining ecosystem and the aligned economic incentives of miners—who benefit more from maintaining network integrity than attacking it—serve as strong deterrents.

This high barrier to control differentiates Bitcoin from smaller or less secure blockchains, which may be more vulnerable to such attacks due to their lower hash rates and centralized mining operations. Ultimately, Bitcoin’s size, decentralization, and economic structure collectively contribute to its resilience against 51% attacks, reinforcing the network’s security and reliability for users worldwide.