Increasing sybil attack detection probability in open-access distributed systems

Sybil attack is the most prominent and challenging attack in open-access distributed systems like peer-to-peer systems. In sybil attack, a malicious user creates multiple fake identities called sybil identities leading to most of the honest nodes in the network to be controlled by them. Many centralized approaches being available, the proposed protocol uses a decentralized approach to defend against sybil attack. The proposed protocol, Extended SybilLimit is an extension of the SybilLimit protocol which leverages social network as a defense against sybil attack. SybilLimit aims at reducing the number of sybil nodes accepted but does not focus in the malicious or false updations that occur during routing. The Extended SybilLimit focuses more on false updation detection thereby increasing the attack detection probability by 5% and also reduces the number of sybil nodes in the system. The Malicious Updation Detection (MUD) algorithm is used to detect the fake updations and it augments to the verification of the suspects in Extended SybilLimit protocol.