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: "active cyber defense dynamics exhibiting rich phenomena"
  Abstract: The Internet is a man-made complex system under constant attacks (e.g., Advanced Persistent Threats and malwares). It is therefore important to understand the phenomena that can be induced by the interaction between cyber attacks and cyber defenses. In this paper, we explore the rich phenomena that can be exhibited when the defender employs active defense to combat cyber attacks. To the best of our knowledge, this is the first study that shows that {\em active cyber defense dynamics} (or more generally, {\em cybersecurity dynamics}) can exhibit the bifurcation and chaos phenomena. This has profound implications for cyber security measurement and prediction: (i) it is infeasible (or even impossible) to accurately measure and predict cyber security under certain circumstances; (ii) the defender must manipulate the dynamics to avoid such {\em unmanageable situations} in real-life defense operations.

Connected through hyperedge HE-1 (induced by source paper "preventive and reactive cyber defense dynamics with ergodic time dependent parameters is globally attractive"):
  with members:
    - "a stochastic model of active cyber defense dynamics"
    - "a stochastic model for quantitative security analyses of networked systems"
    - "a new approach to modeling and analyzing security of networked systems"
    - "preventive and reactive cyber defense dynamics is globally stable"
    - "epidemic threshold of an sis model in dynamic switching networks"
    - "disease spread over randomly switched large scale networks"
    - "characterizing the power of moving target defense via cyber epidemic dynamics"

Connected through hyperedge HE-2 (induced by source paper "a systems thinking for cybersecurity modeling"):
  with members:
    - "insights from nature for cybersecurity"
    - "application of cybernetics and control theory for a new paradigm in cybersecurity"

Connected through hyperedge HE-3 (induced by source paper "a survey on ethereum systems security vulnerabilities attacks and defenses"):
  with members:
    - "security and privacy on blockchain"
    - "exploring the attack surface of blockchain a systematic overview"
    - "a survey on consensus mechanisms and mining strategy management in blockchain networks"
    - "metrics towards measuring cyber agility"
    - "selfish mining in ethereum"
    - "a survey of distributed consensus protocols for blockchain networks"
    - "finding the greedy prodigal and suicidal contracts at scale"
    - "ethir a framework for high level analysis of ethereum bytecode"

Connected through hyperedge HE-4 (induced by source paper "metrics towards measuring cyber agility"):
  with members:
    - "characterizing honeypot captured cyber attacks statistical framework and case study"
    - "a stochastic model of active cyber defense dynamics"
    - "push and pull based epidemic spreading in networks thresholds and deeper insights"
    - "optimizing active cyber defense"
    - "an extended stochastic model for quantitative security analysis of networked systems"
    - "predicting cyber attack rates with extreme values"
    - "cyber epidemic models with dependences"
    - "a new approach to modeling and analyzing security of networked systems"

Connected through hyperedge HE-5 (induced by source paper "node diversification in complex networks by decentralized colouring"):
  with members:
    - "push and pull based epidemic spreading in networks thresholds and deeper insights"
    - "preventive and reactive cyber defense dynamics is globally stable"
    - "distributed deterministic edge coloring using bounded neighborhood independence"

Connected through hyperedge HE-6 (induced by source paper "analysis of the effectiveness of the truth spreading strategy for inhibiting rumors"):
  with members:
    - "a stochastic model of active cyber defense dynamics"
    - "stability of epidemic models over directed graphs a positive systems approach"

Connected through hyperedge HE-7 (induced by source paper "on the effectiveness of the truth spreading rumor blocking strategy for restraining rumors"):
  with members:
    - "a stochastic model of active cyber defense dynamics"

Connected through hyperedge HE-8 (induced by source paper "a survey on security metrics"):
  with members:
    - "characterizing honeypot captured cyber attacks statistical framework and case study"
    - "a stochastic model of active cyber defense dynamics"
    - "a characterization of cybersecurity posture from network telescope data"
    - "an extended stochastic model for quantitative security analysis of networked systems"
    - "predicting cyber attack rates with extreme values"
    - "cyber epidemic models with dependences"
    - "a new approach to modeling and analyzing security of networked systems"
    - "characterizing the power of moving target defense via cyber epidemic dynamics"

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)