Sybil Attack

A Sybil Attack on a network involves a single actor creating multiple identities to gain an outsized influence within the network. This may allow the actor to make a ruling majority on consensus or governance-related matters, enabling censorship of blocks or ratifying falsified transactions.

For peer-to-peer networks such as blockchains, where actors are pseudonymous, it is of fundamental importance that its security is resistant to Sybil Attacks. Since identities, such as addresses or accounts, tend to be easy to create, certain networks distribute voting power based on metrics that cannot be easily gamed, such as hash power or locked stake.