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: "ldpc code design for the bpsk constrained gaussian wiretap channel"
  Abstract: A coding scheme based on irregular low-density parity-check (LDPC) codes is proposed to send secret messages from a source over the Gaussian wiretap channel to a destination in the presence of a wiretapper, with the restriction that the source can send only binary phase-shift-keyed (BPSK) symbols. The secrecy performance of the proposed coding scheme is measured by the secret message rate through the wiretap channel as well as the equivocation rate about the message at the wiretapper. A code search procedure is suggested to obtain irregular LDPC codes that achieve good secrecy performance in such context.

Connected through hyperedge HE-1 (induced by source paper "an overview of physical layer security with finite alphabet signaling"):
  with members:
    - "a survey of physical layer security techniques for 5g wireless networks and challenges ahead"
    - "physical layer cryptography through massive mimo"
    - "linear precoding of data and artificial noise in secure massive mimo systems"
    - "sum secrecy rate maximization for full duplex two way relay networks using alamouti based rank two beamforming"
    - "performance of lattice coset codes on universal software radio peripherals"
    - "secure m psk communication via directional modulation"
    - "finite blocklength bounds for wiretap channels"
    - "physical layer security in millimeter wave cellular networks"

Connected through hyperedge HE-2 (induced by source paper "ldpc based code hopping for gaussian wiretap channel with limited feedback"):
  with members:
    - "coding with scrambling concatenation and harq for the awgn wire tap channel a security gap analysis"
    - "lattice codes for the gaussian wiretap channel"
    - "coding for cryptographic security enhancement using stopping sets"
    - "the secrecy capacity region of the gaussian mimo multi receiver wiretap channel"
    - "the secrecy capacity of the mimo wiretap channel"
    - "applications of ldpc codes to the wiretap channel"

Connected through hyperedge HE-3 (induced by source paper "quantifying equivocation for finite blocklength wiretap codes"):
  with members:
    - "applications of ldpc codes to the wiretap channel"

Connected through hyperedge HE-4 (induced by source paper "on secrecy metrics for physical layer security over quasi static fading channels"):
  with members:
    - "performance assessment and design of finite length ldpc codes for the gaussian wiretap channel"
    - "rethinking the intercept probability of random linear network coding"
    - "probability estimates for fading and wiretap channels from ideal class zeta functions"
    - "secure on off transmission design with channel estimation errors"
    - "wireless physical layer security with imperfect channel state information a survey"
    - "coding with scrambling concatenation and harq for the awgn wire tap channel a security gap analysis"
    - "secret sharing ldpc codes for the bpsk constrained gaussian wiretap channel"
    - "rethinking the secrecy outage formulation a secure transmission design perspective"

Connected through hyperedge HE-5 (induced by source paper "analysis of short blocklength codes for secrecy"):
  with members:
    - "quantifying equivocation for finite blocklength wiretap codes"
    - "performance assessment and design of finite length ldpc codes for the gaussian wiretap channel"
    - "semantically secure lattice codes for the gaussian wiretap channel"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "deterministic constructions for large girth protograph ldpc codes"
    - "coding with scrambling concatenation and harq for the awgn wire tap channel a security gap analysis"
    - "achieving the secrecy capacity of wiretap channels using polar codes"
    - "coding for cryptographic security enhancement using stopping sets"

Connected through hyperedge HE-6 (induced by source paper "performance assessment and design of finite length ldpc codes for the gaussian wiretap channel"):
  with members:
    - "coding with scrambling concatenation and harq for the awgn wire tap channel a security gap analysis"
    - "secret sharing ldpc codes for the bpsk constrained gaussian wiretap channel"
    - "applications of ldpc codes to the wiretap channel"

Connected through hyperedge HE-7 (induced by source paper "ber based physical layer security with finite codelength combining strong converse and error amplification"):
  with members:
    - "performance assessment and design of finite length ldpc codes for the gaussian wiretap channel"
    - "performance analysis and design of two edge type ldpc codes for the bec wiretap channel"
    - "coding with scrambling concatenation and harq for the awgn wire tap channel a security gap analysis"
    - "on secrecy above secrecy capacity"
    - "achieving the secrecy capacity of wiretap channels using polar codes"
    - "strong secrecy on the binary erasure wiretap channel using large girth ldpc codes"
    - "secrecy gain a wiretap lattice code design"
    - "invertible extractors and wiretap protocols"

Connected through hyperedge HE-8 (induced by source paper "coding with scrambling concatenation and harq for the awgn wire tap channel a security gap analysis"):
  with members:
    - "secret sharing ldpc codes for the bpsk constrained gaussian wiretap channel"
    - "increasing physical layer security through scrambled codes and arq"
    - "non systematic codes for physical layer security"
    - "on the throughput of secure hybrid arq protocols for gaussian block fading channels"
    - "arq secrecy from theory to practice"
    - "the wiretap channel with feedback encryption over the 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)