Optimal Sybil-resilient node admission control

—Most existing large-scale networked systems on the Internet such as peer-to-peer systems are vulnerable to Sybil attacks where a single adversary can introduce many bogus identities. One promising defense of Sybil attacks is to perform social-network based admission control to bound the number of Sybil identities admitted. SybilLimit [22], the best known Sybil admission control mechanism, can restrict the number of Sybil identities admitted per attack edge to O(log n) with high probability assuming O(n/ log n) attack edges. In this paper, we propose Gatekeeper, a decentralized Sybilresilient admission control protocol that significantly improves over SybilLimit. Gatekeeper is optimal for the case of O(1) attack edges and admits only O(1) Sybil identities (with high probability) in a random expander social networks (real-world social networks exhibit expander properties). In the face of O(k) attack edges (for any k ∈ O(n/ log n)), Gatekeeper admits O(log k) Sybils per attack edge....

• Type: Journal
• Year: 2011
• Where: INFOCOM
• Authors: Nguyen Tran, Jinyang Li, Lakshminarayanan Subramanian, Sherman S. M. Chow
• Keywords: Admission Control, Communications, Control Protocol, INFOCOM 2011, Sybils