Using Sybil Identities for Primary User Emulation and Byzantine Attacks in DSA Networks

In this paper, we investigate a new type of denialof- service attack in dynamic spectrum access networks - Sybilenabled attack. In this attack, the attacker not only launches the primary user emulation (PUE) attacks but also creates and infiltrates multiple Sybil identities to compromise the decision making process of the secondary network via Byzantine attacks. We implement this attack in our cognitive radio testbed to show its feasibility and attack impact. We further analyze the optimal attack strategy from the perspective of the malicious attacker, i.e., the optimal allocation of Sybil interfaces for different attacks, to maximize the impact on the secondary network. The attack models are analyzed under two different scenarios: with and without a reputation system in the network fusion center. Numerical analysis and simulations are conducted to solve the optimal attack strategy and demonstrate the impact of attacks on the secondary network.