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: "secure diversity multiplexing tradeoff of zero forcing transmit scheme at finite snr"
  Abstract: In this paper, we address the finite Signal-to-Noise Ratio (SNR) Diversity-Multiplexing Tradeoff (DMT) of the Multiple Input Multiple Output (MIMO) wiretap channel, where a Zero-Forcing (ZF) transmit scheme, that intends to send the secret information in the orthogonal space of the eavesdropper channel, is used. First, we introduce the secrecy multiplexing gain at finite-SNR that generalizes the definition at high-SNR. Then, we provide upper and lower bounds on the outage probability under secrecy constraint, from which secrecy diversity gain estimates of ZF are derived. Through asymptotic analysis, we show that the upper bound underestimates the secrecy diversity gain, whereas the lower bound is tight at high-SNR, and thus its related diversity gain estimate is equal to the actual asymptotic secrecy diversity gain of the MIMO wiretap channel.

Connected through hyperedge HE-1 (induced by source paper "joint relay selection and power allocation in large scale mimo systems with untrusted relays and passive eavesdroppers"):
  with members:
    - "joint relay and jammer selection improves the physical layer security in the face of csi feedback delays"
    - "secure massive mimo transmission with an active eavesdropper"
    - "physical layer security for massive mimo an overview on passive eavesdropping and active attacks"
    - "massive mimo for next generation wireless systems"
    - "security versus reliability analysis of opportunistic relaying"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "a simple cooperative diversity method based on network path selection"

Connected through hyperedge HE-2 (induced by source paper "secure communication in uplink transmissions user selection and multiuser secrecy gain"):
  with members:
    - "secure massive mimo transmission with an active eavesdropper"
    - "the ergodic capacity of the multiple access channel under distributed scheduling order optimality of linear receivers"
    - "exact joint distribution analysis of zero forcing v blast gains with greedy ordering"
    - "multiuser diversity for secrecy communications using opportunistic jammer selection secure dof and jammer scaling law"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "robust beamforming for security in mimo wiretap channels with imperfect csi"
    - "secure transmission with artificial noise over fading channels achievable rate and optimal power allocation"
    - "on the secure degrees of freedom of the multiple access channel"

Connected through hyperedge HE-3 (induced by source paper "secrecy capacity scaling in large cooperative wireless networks"):
  with members:
    - "constrained colluding eavesdroppers an information theoretic model"
    - "scaling laws for secrecy capacity in cooperative wireless networks"
    - "multi receiver wiretap channel with public and confidential messages"
    - "an overview of the transmission capacity of wireless networks"
    - "secure transmission with multiple antennas ii the mimome wiretap channel"
    - "towards the secrecy capacity of the gaussian mimo wire tap channel the 2 2 1 channel"
    - "diversity multiplexing tradeoff for the multiple antenna wire tap channel"
    - "discrete memoryless interference and broadcast channels with confidential messages secrecy rate regions"

Connected through hyperedge HE-4 (induced by source paper "scaling laws for secrecy capacity in cooperative wireless networks"):
  with members:
    - "constrained colluding eavesdroppers an information theoretic model"
    - "multi receiver wiretap channel with public and confidential messages"
    - "an overview of the transmission capacity of wireless networks"
    - "secure transmission with multiple antennas ii the mimome wiretap channel"
    - "towards the secrecy capacity of the gaussian mimo wire tap channel the 2 2 1 channel"
    - "diversity multiplexing tradeoff for the multiple antenna wire tap channel"
    - "discrete memoryless interference and broadcast channels with confidential messages secrecy rate regions"
    - "the secrecy capacity of the mimo wiretap channel"

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)