Glossary
Sybil Attack
Creating many fake identities to gain disproportionate influence in a network that treats each identity as one vote or one peer.
Named after the 1973 book "Sybil" about a woman with multiple personalities, a Sybil attack abuses the cheapness of creating identities in a permissionless system. An attacker spins up thousands of fake nodes, voters, or accounts and uses them to overwhelm legitimate participants.
Proof-of-work and proof-of-stake both defeat Sybil attacks by making influence proportional to a real resource — electricity or capital — rather than to identity count. Sybil resistance is a foundational property of any open consensus.