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: "on the delay limited secrecy capacity of fading channels"
  Abstract: In this paper, the delay limited secrecy capacity of the flat fading channel is investigated under two different assumptions on the available transmitter channel state information (CSI). The first scenario assumes perfect prior knowledge of both the main and eavesdropper channel gains. Here, upper and lower bounds on the secure delay limited capacity are derived and shown to be tight in the high signal-to-noise ratio (SNR) regime (for a wide class of channel distributions). In the second scenario, only the main channel CSI is assumed to be available at the transmitter. Remarkably, under this assumption, we establish the achievability of non-zero secure rate (for a wide class of channel distributions) under a strict delay constraint. In the two cases, our achievability arguments are based on a novel twostage approach that overcomes the secrecy outage phenomenon observed in earlier works.

Connected through hyperedge HE-1 (induced by source paper "secret key aided scheme for securing untrusted df relaying networks"):
  with members:
    - "achievable rates of buffer aided full duplex gaussian relay channels"
    - "protecting against untrusted relays an information self encrypted approach"
    - "capacity of the gaussian two hop full duplex relay channel with residual self interference"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "improving physical layer secrecy using full duplex jamming receivers"
    - "experiment driven characterization of full duplex wireless systems"
    - "cooperation with an untrusted relay a secrecy perspective"

Connected through hyperedge HE-2 (induced by source paper "opportunistic secrecy with a strict delay constraint"):
  with members:
    - "secret key agreement with channel state information at the transmitter"
    - "energy efficient scheduling of delay constrained traffic over fading channels"

Connected through hyperedge HE-3 (induced by source paper "secrecy via sources and channels"):
  with members:
    - "secret key generation using correlated sources and channels"
    - "secret key agreement with channel state information at the transmitter"

Connected through hyperedge HE-4 (induced by source paper "secure wireless communication and optimal power control under statistical queueing constraints"):
  with members:
    - "secure broadcasting over fading channels with statistical qos constraints"
    - "secure communication over fading channels with statistical qos constraints"
    - "the impact of qos constraints on the energy efficiency of fixed rate wireless transmissions"
    - "discrete memoryless interference and broadcast channels with confidential messages secrecy rate regions"
    - "secrecy capacity of a class of broadcast channels with an eavesdropper"
    - "analysis of energy efficiency in fading channels under qos constraints"

Connected through hyperedge HE-5 (induced by source paper "diversity multiplexing tradeoff for the multiple antenna wire tap channel"):
  with members:
    - "opportunistic secrecy with a strict delay constraint"
    - "interference alignment for secrecy"
    - "mimo wiretap channels with arbitrarily varying eavesdropper channel states"
    - "secure transmission with multiple antennas ii the mimome wiretap channel"
    - "secured communication over frequency selective fading channels a practical vandermonde precoding"
    - "towards the secrecy capacity of the gaussian mimo wire tap channel the 2 2 1 channel"
    - "on the compound mimo broadcast channels with confidential messages"
    - "discrete memoryless interference and broadcast channels with confidential messages secrecy rate regions"

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.IT(Information Theory)