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: "security a perpetual war lessons from nature"
  Abstract: For ages people have sought inspiration in nature. Biomimicry has been the propelling power of such inventions, like Velcro tape or "cat's eyes" - retroreflective road marking. At the same time, scientists have been developing biologically inspired techniques: genetic algorithms, neural and sensor networks, etc. Although at a first glance there is no direct inspiration behind offensive and defensive techniques seen in the Internet and the patterns present in nature, closer inspection reveals many analogies between these two worlds. Botnets, DDoS (Distributed Denial of Service) attacks, IDS/IPSs (Intrusion Detection/Prevention Systems), and others, all employ strategies which very closely resemble actions undertaken by certain species of the kingdoms of living things. The main conclusion of the analysis is that security community should turn to nature in search of new offensive and defensive techniques for virtual world security.

Connected through hyperedge HE-1 (induced by source paper "software defined networking based crypto ransomware detection using http traffic characteristics"):
  with members:
    - "automated dynamic analysis of ransomware benefits limitations and use for detection"
    - "using software defined networking for ransomware mitigation the case of cryptowall"
    - "software defined networking a comprehensive survey"

Connected through hyperedge HE-2 (induced by source paper "ecology based dos attack in cognitive radio networks"):
  with members:
    - "towards a systematic view on cybersecurity ecology"
    - "byzantine attack and defense in cognitive radio networks a survey"
    - "sequential defense against random and intentional attacks in complex networks"

Connected through hyperedge HE-3 (induced by source paper "decapitation via digital epidemics a bio inspired transmissive attack"):
  with members:
    - "ecology based dos attack in cognitive radio networks"
    - "buffer occupancy and delivery reliability tradeoffs for epidemic routing"

Connected through hyperedge HE-4 (induced by source paper "creativity in mind evaluating and maintaining advances in network steganographic research"):
  with members:
    - "principles and overview of network steganography"
    - "steganography of voip streams"

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)