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 power allocation by imperfect hardware analysis in untrusted relaying networks"
  Abstract: By taking a variety of realistic hardware imperfections into consideration, we propose an optimal power allocation (OPA) strategy to maximize the instantaneous secrecy rate of a cooperative wireless network comprised of a source, a destination and an untrusted amplify-and-forward (AF) relay. We assume that either the source or the destination is equipped with a large-scale multiple antennas (LSMA) system, while the rest are equipped with a single antenna. To prevent the untrusted relay from intercepting the source message, the destination sends an intended jamming noise to the relay, which is referred to as destination-based cooperative jamming (DBCJ). Given this system model, novel closed-form expressions are presented in the high signal-to-noise ratio (SNR) regime for the ergodic secrecy rate (ESR) and the secrecy outage probability (SOP). We further improve the secrecy performance of the system by optimizing the associated hardware design. The results reveal that by beneficially distributing the tolerable hardware imperfections across the transmission and reception radio-frequency (RF) front ends of each node, the system's secrecy rate may be improved. The engineering insight is that equally sharing the total imperfections at the relay between the transmitter and the receiver provides the best secrecy performance. Numerical results illustrate that the proposed OPA together with the most appropriate hardware design significantly increases the secrecy rate.

Connected through hyperedge HE-1 (induced by source paper "design and performance analysis of secure multicasting cooperative protocol for wireless sensor network applications"):
  with members:
    - "cooperation with an untrusted relay a secrecy perspective"

Connected through hyperedge HE-2 (induced by source paper "secure transmission with covert requirement in untrusted relaying networks"):
  with members:
    - "covert communications versus physical layer security"
    - "joint relay selection and power allocation in large scale mimo systems with untrusted relays and passive eavesdroppers"
    - "covert communication achieved by a greedy relay in wireless networks"
    - "on covert communication with noise uncertainty"
    - "covert communication in the presence of an uninformed jammer"
    - "joint relay and jammer selection improves the physical layer security in the face of csi feedback delays"
    - "secrecy transmit beamforming for heterogeneous networks"
    - "massive mimo for next generation wireless systems"

Connected through hyperedge HE-3 (induced by source paper "resource allocation for secure gaussian parallel relay channels with finite length coding and discrete constellations"):
  with members:
    - "enhancing physical layer security in af relay assisted multicarrier wireless transmission enhancing physical layer security in af relay assisted multicarrier wireless transmission"
    - "joint relay selection and power allocation in large scale mimo systems with untrusted relays and passive eavesdroppers"
    - "secrecy optimized resource allocation for device to device communication underlaying heterogeneous networks"
    - "secure communication over parallel relay channel"
    - "secure and reliable transmission with cooperative relays in two hop wireless networks"
    - "on secrecy rate analysis of mimo wiretap channels driven by finite alphabet input"
    - "on cooperative relaying schemes for wireless physical layer security"
    - "sum rate maximized resource allocation in multiple df relays aided ofdm transmission"

Connected through hyperedge HE-4 (induced by source paper "covert communications versus physical layer security"):
  with members:
    - "joint relay selection and power allocation in large scale mimo systems with untrusted relays and passive eavesdroppers"
    - "covert communication in the presence of an uninformed jammer"

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)