# Game Theory Meets Wireless Sensor Networks Security Requirements and Threats Mitigation: A Survey
## 4 Game Theory Defense Strategies Against WSN Attacks
### Cooperative and Non-Cooperative Games
#### 4.4.2 Non-Cooperative Games
The reactive jammer seeks to inject noise like legitimate signal at receiver. The utility function is represented by the resulting SINR, while a linear power penalty is used as a punishment for jammer and legitimate nodes. In [57], a Stackelberg game is developed to confront the external attacks manipulations based on energy defense budget against the corresponding energy attack budget. The utility function represents the resultant of the defense and attack energy budgets. * **Jamming Game**: In [58], the authors propose a jamming game that is fundamentally inspired from the zero-sum game framework due to the uniqueness of NE. More concretely, the authors study the jamming impact on the Orthogonal Frequency Division Multiplexing (OFDM) system when the jammer is situated close to the base station. The utility function is the combination of the power level of the uncontrolled environmental noise at \(i\)-th state, the costs of power usage for transmitter and jammer, and fading channel gains for transmitter and jammer. In [59], a jamming game is proposed to mitigate the DoS attack (jamming attack) in underwater sensor network. The legal player utility function is maximized based on a combination of its power level, SINR, and transmission costs. The game model is classified into two cases. In the former case, the game is presented as a static jamming game that owns a single NE. In the latter case, the game is represented by a dynamic jamming game which is derived based on a Markov decision process. In other work, the jamming game is used to treat the complexity constraints of implanted biomedical sensors [60; 61]. In these models, the utility function is presented in two cases. In the former case, the authors study a fixed strategy in which the jammer may or may not jam the \(i\)-th player. In the latter case, a mixed transmission strategy is used for the \(i\)-th player. * **Stochastic Game**: In [64], the authors propose a new framework for wireless nodes virtualization in which the service providers and network operators are responsible for the QoS and spectrum management, respectively. The proposed model can handle the unknown dynamics in traffic characteristics and channel conditions. In addition, the network operator is responsible for calculating the NE based on the conjectural price of the communicating nodes leading to the optimal resource management. * **Bayesian Game**: In [66], a Bayesian game is proposed to analyze the interactions between pairs of attacking/defending nodes. The Nash equilibrium is studied for the attacker/defender game through two scenarios, namely, static and dynamic. In fact, the dynamic Bayesian model represents the more realistic approach that allows the network defender to continuously update his decision for the existing malicious nodes. Furthermore, the dynamic scenario provides energy-efficient monitoring strategies for the defender. A new approach is suggested called Bayesian hybrid detection that adopts lightweight monitoring and heavyweight monitoring mechanisms. The lightweight monitoring is utilized to estimate the adversary's actions, while the heavyweight monitoring acts as a last resort of defense. * **Evolutionary Game**: In [67], the authors propose a data aggregation model called evolutionary game-based data aggregation model (EGDAM) in WSNs. The model uses a weighting method based on the pixel-level fusion between homogeneous sensor nodes to adapt the unreliable information from the nodes. In [68], an evolutionary game is used to maintain the cooperation in static and mobile multi-class WSNs, with each class managed by a different authority. Two scenarios are considered for the packet forwarding. In the former scenario, the packet forwarding is between mobile classes in which the game formulation is based on iterated prisoner dilemma. In the later scenario, the packet forwarding is between spatially dispersed stationary classes.