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: "cooperative jamming for wireless physical layer security"
  Abstract: Cooperative jamming is an approach that has been recently proposed for improving physical layer based security for wireless networks in the presence of an eavesdropper. While the source transmits its message to its destination, a relay node transmits a jamming signal to create interference at the eavesdropper. In this paper, a scenario in which the relay is equipped with multiple antennas is considered. A novel system design is proposed for determining the antenna weights and transmit power of source and relay, so that the system secrecy rate is maximized subject to a total transmit power constraint, or, the transmit power is minimized subject to a secrecy rate constraint. Since the optimal solutions to these problems are difficult to obtain, suboptimal closed-form solutions are proposed that introduce an additional constraint, i.e., the complete nulling of jamming signal at the destination.

Connected through hyperedge HE-1 (induced by source paper "wireless side lobe eavesdropping attacks"):
  with members:
    - "physical layer security in millimeter wave cellular networks"
    - "secure communications in millimeter wave ad hoc networks"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "enhancing secrecy with multi antenna transmission in wireless ad hoc networks"

Connected through hyperedge HE-2 (induced by source paper "energy efficient secrecy in wireless networks based on random jamming"):
  with members:
    - "energy efficient routing in wireless networks in the presence of jamming"
    - "optimal energy and data routing in networks with energy cooperation"
    - "jamming based on an ephemeral key to obtain everlasting security in wireless environments"
    - "secure degrees of freedom of one hop wireless networks"
    - "scaling laws for secrecy capacity in cooperative wireless networks"
    - "optimal relay selection for physical layer security in cooperative wireless networks"
    - "efficient wireless security through jamming coding and routing"
    - "everlasting secrecy by exploiting non idealities of the eavesdropper s receiver"

Connected through hyperedge HE-3 (induced by source paper "security of rechargeable energy harvesting transmitters in wireless networks"):
  with members:
    - "wireless networks with rf energy harvesting a contemporary survey"

Connected through hyperedge HE-4 (induced by source paper "jamming based on an ephemeral key to obtain everlasting security in wireless environments"):
  with members:
    - "everlasting secrecy by exploiting non idealities of the eavesdropper s receiver"
    - "cooperative jamming for secure communications in mimo relay networks"

Connected through hyperedge HE-5 (induced by source paper "a new distributed dc programming method and its applications"):
  with members:
    - "signal processing and optimal resource allocation for the interference channel"
    - "decomposition by partial linearization parallel optimization of multi agent systems"
    - "joint sensing and power allocation in nonconvex cognitive radio games quasi nash equilibria"
    - "joint sensing and power allocation in nonconvex cognitive radio games nash equilibria and distributed algorithms"
    - "distributed optimal beamformers for cognitive radios robust to channel uncertainties"
    - "on cooperative relaying schemes for wireless physical layer security"
    - "dynamic resource allocation in cognitive radio networks"

Connected through hyperedge HE-6 (induced by source paper "outage constrained secrecy rate maximization using cooperative jamming"):
  with members:
    - "secure transmission with multiple antennas ii the mimome wiretap channel"
    - "the secrecy capacity of the mimo wiretap channel"
    - "the general gaussian multiple access and two way wire tap channels achievable rates and cooperative jamming"

Connected through hyperedge HE-7 (induced by source paper "physical layer security with uncoordinated helpers implementing cooperative jamming"):
  with members:
    - "on cooperative relaying schemes for wireless physical layer security"

Connected through hyperedge HE-8 (induced by source paper "solutions for the mimo gaussian wiretap channel with a cooperative jammer"):
  with members:
    - "new results on multiple input multiple output broadcast channels with confidential messages"
    - "secure transmission with multiple antennas ii the mimome wiretap channel"
    - "transmitter optimization for achieving secrecy capacity in gaussian mimo wiretap channels"
    - "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.IT(Information Theory)