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 secure degrees of freedom of the multiple access channel"
  Abstract: A $K$-user secure Gaussian Multiple-Access-Channel (MAC) with an external eavesdropper is considered in this paper. An achievable rate region is established for the secure discrete memoryless MAC. The secrecy sum capacity of the degraded Gaussian MIMO MAC is proven using Gaussian codebooks. For the non-degraded Gaussian MIMO MAC, an algorithm inspired by interference alignment technique is proposed to achieve the largest possible total Secure-Degrees-of-Freedom (S-DoF). When all the terminals are equipped with a single antenna, Gaussian codebooks have shown to be inefficient in providing a positive S-DoF. Instead, a novel secure coding scheme is proposed to achieve a positive S-DoF in the single antenna MAC. This scheme converts the single-antenna system into a multiple-dimension system with fractional dimensions. The achievability scheme is based on the alignment of signals into a small sub-space at the eavesdropper, and the simultaneous separation of the signals at the intended receiver. Tools from the field of Diophantine Approximation in number theory are used to analyze the probability of error in the coding scheme. It is proven that the total S-DoF of $\frac{K-1}{K}$ can be achieved for almost all channel gains. For the other channel gains, a multi-layer coding scheme is proposed to achieve a positive S-DoF. As a function of channel gains, therefore, the achievable S-DoF is discontinued.

Connected through hyperedge HE-1 (induced by source paper "adding common randomness can remove the secrecy constraints in communication networks"):
  with members:
    - "secure communication over interference channel to jam or not to jam"
    - "adding a helper can totally remove the secrecy constraints in interference channel"
    - "optimal secure gdof of symmetric gaussian wiretap channel with a helper"
    - "secure degrees of freedom of one hop wireless networks with no eavesdropper csit"
    - "towards a constant gap sum capacity result for the gaussian wiretap channel with a helper"
    - "finite snr regime analysis of the gaussian wiretap multiple access channel"
    - "secure degrees of freedom of one hop wireless networks"
    - "real interference alignment exploiting the potential of single antenna systems"

Connected through hyperedge HE-2 (induced by source paper "secure degrees of freedom regions of multiple access and interference channels the polytope structure"):
  with members:
    - "secure degrees of freedom of one hop wireless networks"
    - "real interference alignment exploiting the potential of single antenna systems"
    - "secure degrees of freedom of the gaussian wiretap channel with helpers and no eavesdropper csi blind cooperative jamming"
    - "secure degrees of freedom of k user gaussian interference channels a unified view"
    - "interference alignment for secrecy"
    - "ergodic secret alignment"
    - "cooperation with an untrusted relay a secrecy perspective"
    - "real interference alignment with real numbers"

Connected through hyperedge HE-3 (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"
    - "secure diversity multiplexing tradeoff of zero forcing transmit scheme at finite snr"
    - "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"

Connected through hyperedge HE-4 (induced by source paper "on the secure degrees of freedom of the k user mac and 2 user interference channels"):
  with members:
    - "the secrecy capacity region of the gaussian mimo multi receiver wiretap channel"
    - "secrecy in cooperative relay broadcast channels"
    - "achievable rates for the general gaussian multiple access wire tap channel with collective secrecy"

Connected through hyperedge HE-5 (induced by source paper "secure degrees of freedom of multi user networks one time pads in the air via alignment"):
  with members:
    - "secure degrees of freedom of one hop wireless networks"
    - "real interference alignment exploiting the potential of single antenna systems"
    - "secure degrees of freedom of the gaussian wiretap channel with helpers and no eavesdropper csi blind cooperative jamming"
    - "new results on multiple input multiple output broadcast channels with confidential messages"
    - "interference alignment for secrecy"
    - "strongly secure communications over the two way wiretap channel"
    - "ergodic secret alignment"
    - "cooperation with an untrusted relay a secrecy perspective"

Connected through hyperedge HE-6 (induced by source paper "secure degrees of freedom of wireless x networks using artificial noise alignment"):
  with members:
    - "secure degrees of freedom of one hop wireless networks"
    - "multiaccess channel with partially cooperating encoders and security constraints"
    - "secure degrees of freedom of k user gaussian interference channels a unified view"
    - "secure degrees of freedom of mimo x channels with output feedback and delayed csit"
    - "on x channels with feedback and delayed csi"
    - "secure communication over parallel relay channel"
    - "on achievable degrees of freedom for mimo x channels"
    - "interference alignment for secrecy"

Connected through hyperedge HE-7 (induced by source paper "finite snr regime analysis of the gaussian wiretap multiple access channel"):
  with members:
    - "compute and forward can buy secrecy cheap"
    - "secure degrees of freedom of one hop wireless networks"
    - "the approximate sum capacity of the symmetric gaussian k user interference channel"
    - "compute and forward harnessing interference through structured codes"
    - "on the role of mmse estimation in approaching the information theoretic limits of linear gaussian channels shannon meets wiener"

Connected through hyperedge HE-8 (induced by source paper "compute and forward can buy secrecy cheap"):
  with members:
    - "secure degrees of freedom of one hop wireless networks"
    - "the approximate sum capacity of the symmetric gaussian k user interference channel"
    - "compute and forward harnessing interference through structured codes"
    - "on the role of mmse estimation in approaching the information theoretic limits of linear gaussian channels shannon meets wiener"

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)