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: "principles and overview of network steganography"
  Abstract: The paper presents basic principles of network steganography, which is a comparatively new research subject in the area of information hiding, followed by a concise overview and classification of network steganographic methods and techniques.

Connected through hyperedge HE-1 (induced by source paper "real time steganalysis for stream media based on multi channel convolutional sliding windows"):
  with members:
    - "clinical assistant diagnosis for electronic medical record based on convolutional neural network"
    - "automatically generate steganographic text based on markov model and huffman coding"
    - "how to augment a small learning set for improving the performances of a cnn based steganalyzer"
    - "generating steganographic text with lstms"
    - "a novel convolutional neural network for image steganalysis with shared normalization"
    - "image captioning with object detection and localization"
    - "densely connected convolutional networks"
    - "fractalnet ultra deep neural networks without residuals"

Connected through hyperedge HE-2 (induced by source paper "hiding data in plain sight undetectable wireless communications through pseudo noise asymmetric shift keying"):
  with members:
    - "defeating jamming with the power of silence a game theoretic analysis"
    - "practical covert channels for wifi systems"
    - "hidden and uncontrolled on the emergence of network steganographic threats"
    - "hiding data in ofdm symbols of ieee 802 11 networks"

Connected through hyperedge HE-3 (induced by source paper "trends toward real time network data steganography"):
  with members:
    - "steganography of voip streams"

Connected through hyperedge HE-4 (induced by source paper "creativity in mind evaluating and maintaining advances in network steganographic research"):
  with members:
    - "security a perpetual war lessons from nature"
    - "steganography of voip streams"

Connected through hyperedge HE-5 (induced by source paper "steganography in modern smartphones and mitigation techniques"):
  with members:
    - "steganography using the extensible messaging and presence protocol xmpp"
    - "stegtorrent a steganographic method for the p2p file sharing service"
    - "voip steganography and its detection a survey"
    - "using transcoding for hidden communication in ip telephony"
    - "lost audio packets steganography the first practical evaluation"
    - "capacity of steganographic channels"
    - "lack a voip steganographic method"

Connected through hyperedge HE-6 (induced by source paper "improving hard disk contention based covert channel in cloud computing environment"):
  with members:
    - "is cloud computing steganography proof"
    - "determinating timing channels in compute clouds"

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)