Sybil attack definition
A Sybil attack is a type of security threat in peer-to-peer (P2P) networks where a node in the network operates under multiple identities. Named after the subject of a book dealing with dissociative identity disorder, it undermines the assumption that each node has only one identity, which often underlies the mechanism of distributed systems.
During a Sybil attack, the hacker creates multiple fake identities or takes over existing ones, using them to gain a disproportionate influence in the network. These fake identities, known as Sybils, can be used to vote multiple times, spread false information, or disrupt network operations. Sybil attacks can target various P2P networks, including file-sharing networks, decentralized online marketplaces, and blockchain systems.
See also: node
Preventing Sybil attacks
Despite mitigation efforts, Sybil attacks continue to be a significant threat to P2P networks due to the inherent challenges of decentralized identity verification. Ongoing research in this field aims to design more effective defenses, but it remains a critical area of concern for P2P network security. There are a few measures you can take to avoid Sybil attacks:
- Limit identity creation. Restricting the rate at which new identities can be created can slow down a potential Sybil attack.
- Proof of work or stake. In blockchain systems, requiring proof of work or stake for each node can make Sybil attacks more costly and, therefore, less likely.
- Identity verification. Implementing robust identity verification can help ensure that each identity corresponds to a unique individual or device.