Security Analysis on Defenses against Sybil Attacks in Wireless Sensor Networks

Few security mechanisms in wireless sensor networks (WSNs) have been implemented, and even fewer have been applied in real deployments. The limited resources of each sensor node makes security in WSNs hard, as the tradeoff between security and practicality must be carefully considered. While there are many types of security attacks in WSNs, we have decided to focus our analysis on a particularly harmful one: the Sybil attack. We apply two security metrics (resiliency and connectivity) and three practicality metrics (processing, storage, and communication complexity) to each of the major proposed defenses against the Sybil attack that we are aware of for analysis and evaluation. We conclude that while such metrics are a good indicator of the security and practicality tradeoffs, they alone are not enough to determine a defense’s usability. They must be used in addition to other qualitative evaluations as well. We believe that additional research and experimentation with new metrics is necessary for further insight.