Sybil Attack

A Sybil attack occurs when an attacker creates multiple fake identities to gain control of a decentralized network or service. In a blockchain network, Sybil attacks can target consensus mechanisms, such as staking or voting, where having more identities or nodes gives more influence. The attacker can then manipulate the network's operations, such as altering transaction history or disrupting governance processes. To defend against Sybil attacks, many blockchain networks use mechanisms like Proof of Work (PoW), Proof of Stake (PoS), and reputation systems that make it costly or difficult for a malicious entity to create multiple identities. Example: In a PoS network, an attacker would need to stake significant amounts of cryptocurrency across multiple identities to execute a Sybil attack, making it economically unviable.