3.3.4 Sybil Attacks

Sybil Attacks

• Mechanism: A Sybil Attack occurs when an attacker creates multiple fake identities or nodes within a network in an attempt to gain disproportionate influence over the consensus process. In blockchain networks, a Sybil attack involves an attacker controlling a significant portion of the network nodes, which can manipulate the network’s decisions.

• Impact: If the attacker controls enough nodes, they can influence or alter consensus decisions, prevent transactions from being confirmed, or perform a double-spending attack.

Prevention: To prevent Sybil attacks, blockchain networks use Proof of Work (PoW), Proof of Stake (PoS), or similar mechanisms where participants must prove their work or stake to avoid the creation of fake identities. Identity validation systems and reputation mechanisms are also commonly used to defend against these attacks.