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: "optimal signaling for secure communications over gaussian mimo wiretap channels"
  Abstract: Optimal signalling over the Gaussian MIMO wire-tap channel is studied under the total transmit power constraint. A closed-form solution for an optimal transmit covariance matrix is obtained when the channel is strictly degraded. In combination with the rank-1 solution, this provides the complete characterization of the optimal covariance for the case of two transmit antennas. The cases of weak eavesdropper and high SNR are considered. It is shown that the optimal covariance does not converge to a scaled identity in the high-SNR regime. Necessary optimality conditions and a tight upper bound on the rank of an optimal covariance matrix are established for the general case, along with a lower bound to the secrecy capacity, which is tight in a number of scenarios.

Connected through hyperedge HE-1 (induced by source paper "semantically secure lattice codes for compound mimo channels"):
  with members:
    - "random ensembles of lattices from generalized reductions"
    - "universal lattice codes for mimo channels"
    - "a general formula for compound channel capacity"
    - "the secrecy capacity of compound gaussian mimo wiretap channels"
    - "the mimo wiretap channel decomposed"
    - "construction a of lattices over number fields and block fading wiretap coding"
    - "probability estimates for fading and wiretap channels from ideal class zeta functions"
    - "achieving secrecy capacity of the wiretap channel and broadcast channel with a confidential component"

Connected through hyperedge HE-2 (induced by source paper "a rotation based method for precoding in gaussian mimome channels"):
  with members:
    - "noma an information theoretic perspective"
    - "optimal beamforming for gaussian mimo wiretap channels with two transmit antennas"
    - "an algorithm for global maximization of secrecy rates in gaussian mimo wiretap channels"
    - "full rank solutions for the mimo gaussian wiretap channel with an average power constraint"
    - "cooperative jamming for secure communications in mimo relay networks"
    - "towards the secrecy capacity of the gaussian mimo wire tap channel the 2 2 1 channel"
    - "transmitter optimization for achieving secrecy capacity in gaussian mimo wiretap channels"
    - "the secrecy capacity of the mimo wiretap channel"

Connected through hyperedge HE-3 (induced by source paper "secrecy rate of distributed cooperative mimo in the presence of multi antenna eavesdropper"):
  with members:
    - "cooperative secure transmission by exploiting social ties in random networks"
    - "on secrecy performance of antenna selection aided mimo systems against eavesdropping"
    - "optimization of code rates in sisome wiretap channels"
    - "secure and green swipt in distributed antenna networks with limited backhaul capacity"
    - "power allocation in mimo wiretap channel with statistical csi and finite alphabet input"
    - "on secrecy capacity of fast fading mimome wiretap channels with statistical csit"
    - "full rank solutions for the mimo gaussian wiretap channel with an average power constraint"
    - "on secrecy rate of the generalized artificial noise assisted secure beamforming for wiretap channels"

Connected through hyperedge HE-4 (induced by source paper "optimal beamforming for gaussian mimo wiretap channels with two transmit antennas"):
  with members:
    - "an algorithm for global maximization of secrecy rates in gaussian mimo wiretap channels"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "full rank solutions for the mimo gaussian wiretap channel with an average power constraint"
    - "on secrecy rate analysis of mimo wiretap channels driven by finite alphabet input"
    - "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"
    - "transmitter optimization for achieving secrecy capacity in gaussian mimo wiretap channels"
    - "the secrecy capacity of the mimo wiretap channel"

Connected through hyperedge HE-5 (induced by source paper "the mimo wiretap channel decomposed"):
  with members:
    - "an algorithm for global maximization of secrecy rates in gaussian mimo wiretap channels"
    - "joint unitary triangularization for gaussian multi user mimo networks"
    - "semantically secure coding scheme achieving the capacity of a gaussian wiretap channel"
    - "joint unitary triangularization for mimo networks"
    - "achieving the secrecy capacity of wiretap channels using polar codes"
    - "strong secrecy from channel resolvability"
    - "construction of wiretap codes from ordinary channel codes"
    - "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)