human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "bad data injection attack and defense in electricity market using game theory study"
  Abstract: Applications of cyber technologies improve the quality of monitoring and decision making in smart grid. These cyber technologies are vulnerable to malicious attacks, and compromising them can have serious technical and economical problems. This paper specifies the effect of compromising each measurement on the price of electricity, so that the attacker is able to change the prices in the desired direction (increasing or decreasing). Attacking and defending all measurements are impossible for the attacker and defender, respectively. This situation is modeled as a zero-sum game between the attacker and defender. The game defines the proportion of times that the attacker and defender like to attack and defend different measurements, respectively. From the simulation results based on the PJM 5-Bus test system, we can show the effectiveness and properties of the studied game.

Connected through hyperedge HE-1 (induced by source paper "state of the art of cyber physical systems security an automatic control perspective"):
  with members:
    - "on redundant observability from security index to attack detection and resilient state estimation"
    - "detection of sensor attack and resilient state estimation for uniformly observable nonlinear systems having redundant sensors"
    - "analysis of stochastic switched systems with application to networked control under jamming attacks"
    - "coding schemes for securing cyber physical systems against stealthy data injection attacks"
    - "detecting integrity attacks on control systems using a moving target approach"
    - "a moving horizon hybrid stochastic game for secure control of cyber physical systems"
    - "modeling and performance evaluation of stealthy false data injection attacks on smart grid in the presence of corrupted measurements"
    - "state estimation with secrecy against eavesdroppers"

Connected through hyperedge HE-2 (induced by source paper "a survey on modality characteristics performance evaluation metrics and security for traditional and wearable biometric systems"):
  with members:
    - "survey on synchrophasor data quality and cybersecurity challenges and evaluation of their interdependencies"
    - "secure management of low power fitness trackers"
    - "secure management of low power fitness trackers"
    - "handwritten signature verification using hand worn devices"
    - "evolution toward 5g multi tier cellular wireless networks an interference management perspective"
    - "an overview of face liveness detection"
    - "enhancing the accuracy of biometric feature extraction fusion using gabor filter and mahalanobis distance algorithm"
    - "fast computation of the performance evaluation of biometric systems application to multibiometrics"

Connected through hyperedge HE-3 (induced by source paper "performance and resilience of cyber physical control systems with reactive attack mitigation"):
  with members:
    - "optimal attack against cyber physical control systems with reactive attack mitigation"
    - "data injection attacks on smart grids with multiple adversaries a game theoretic perspective"
    - "design and stability of load side primary frequency control in power systems"
    - "playing atari with deep reinforcement learning"

Connected through hyperedge HE-4 (induced by source paper "moving target defense for detecting coordinated cyber physical attacks in power grids"):
  with members:
    - "data injection attacks on smart grids with multiple adversaries a game theoretic perspective"

Connected through hyperedge HE-5 (induced by source paper "developing a correlation index to identify coordinated cyber attacks to power grids"):
  with members:
    - "vulnerability analysis and consequences of false data injection attack on power system state estimation"

Connected through hyperedge HE-6 (induced by source paper "data injection attacks on smart grids with multiple adversaries a game theoretic perspective"):
  with members:
    - "quality of service provisioning in decentralized networks a satisfaction equilibrium approach"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.CR(Cryptography and Security)