Exploiting Temporal Dynamics in Sybil Defenses

Sybil attacks present a significant threat to many Internet systems and applications, in which a single adversary inserts multiple colluding identities in the system to compromise its security and privacy. Recent work has advocated the use of social-network-based trust relationships to defend against Sybil attacks. However, most of the prior security analyses of such systems examine only the case of social networks at a single instant in time. In practice, social network connections change over time, and attackers can also cause limited changes to the networks. In this work, we focus on the temporal dynamics of a variety of social-network-based Sybil defenses. We describe and examine the effect of novel attacks based on: (a) the attacker’s ability to modify Sybilcontrolled parts of the social-network graph, (b) his ability to change the connections that his Sybil identities maintain to honest users, and (c) taking advantage of the regular dynamics of connections forming and breaki...

• Type: Journal
• Year: 2015
• Where: CCS
• Authors: Changchang Liu, Peng Gao, Matthew K. Wright, Prateek Mittal
• Keywords: CCS 2015, Security Privacy