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: "two hop secure communication using an untrusted relay"
  Abstract: We consider a source-destination pair that can only communicate through an untrusted intermediate relay node. The intermediate node is willing to employ a designated relaying scheme to facilitate reliable communication between the source and the destination. Yet, the information it relays needs to be kept secret from it. In this two-hop communication scenario, where the use of the untrusted relay node is essential, we find that a positive secrecy rate is achievable. The center piece of the achievability scheme is the help provided by either the destination node with transmission capability, or an external "good samaritan" node. In either case, the helper performs cooperative jamming that confuses the eavesdropping relay and disables it from being able to decipher what it is relaying. We next derive an upper bound on the secrecy rate for this system. We observe that the gap between the upper bound and the achievable rate vanishes as the power of the relay node goes to infinity. Overall, the paper presents a case for intentional interference, i.e., cooperative jamming, as an enabler for secure communication.

Connected through hyperedge HE-1 (induced by source paper "group secret key generation using algebraic rings in three user wireless networks"):
  with members:
    - "insider attacks on physical layer group secret key generation in wireless networks"
    - "the effect of eavesdropper s statistics in experimental wireless secret key generation"
    - "secret key generation from gaussian sources using lattice hashing"
    - "exploiting channel diversity in secret key generation from multipath fading randomness"
    - "information theoretically secret key generation for fading wireless channels"
    - "group secret key generation algorithms"

Connected through hyperedge HE-2 (induced by source paper "secure communication via a wireless energy harvesting untrusted relay"):
  with members:
    - "rf based energy harvesting in decode and forward relaying systems ergodic and outage capacities"
    - "relay selection for wireless communications against eavesdropping a security reliability trade off perspective"
    - "secrecy wireless information and power transfer in fading wiretap channel"
    - "wireless powered relays in cooperative communications time switching relaying protocols and throughput analysis"
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "interference assisted wireless energy harvesting in cognitive relay network with multiple primary transceivers"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "wireless networks with rf energy harvesting a contemporary survey"

Connected through hyperedge HE-3 (induced by source paper "secure transmission on the two hop relay channel with scaled compute and forward"):
  with members:
    - "gaussian multiple access via compute and forward"
    - "secure compute and forward in a bidirectional relay"
    - "near optimal modulo and forward scheme for the untrusted relay channel"
    - "nested lattice codes for secure bidirectional relaying with asymmetric channel gains"
    - "asymmetric compute and forward with csit"
    - "reliable physical layer network coding"
    - "strong secrecy and reliable byzantine detection in the presence of an untrusted relay"
    - "compute and forward harnessing interference through structured codes"

Connected through hyperedge HE-4 (induced by source paper "secure beamforming for mimo two way communications with an untrusted relay"):
  with members:
    - "secure communication via an untrusted non regenerative relay in fading channels"
    - "joint source and relay precoding designs for mimo two way relaying based on mse criterion"
    - "relay placement for physical layer security a secure connection perspective"
    - "joint relay and jammer selection for secure two way relay networks"
    - "cooperative jamming for secure communications in mimo relay networks"
    - "cooperation with an untrusted relay a secrecy perspective"
    - "optimal beamforming for two way multi antenna relay channel with analogue network coding"

Connected through hyperedge HE-5 (induced by source paper "secure communication via an untrusted non regenerative relay in fading channels"):
  with members:
    - "robust secure transmission in miso channels based on worst case optimization"
    - "rethinking the secrecy outage formulation a secure transmission design perspective"
    - "cooperative jamming for secure communications in mimo relay networks"
    - "cooperation with an untrusted relay a secrecy perspective"

Connected through hyperedge HE-6 (induced by source paper "imbalanced beamforming by a multi antenna source for secure utilization of an untrusted relay"):
  with members:
    - "secure communication via an untrusted non regenerative relay in fading channels"
    - "robust beamforming for security in mimo wiretap channels with imperfect csi"
    - "cooperation with an untrusted relay a secrecy perspective"

Connected through hyperedge HE-7 (induced by source paper "cooperative jamming for secure communications in mimo relay networks"):
  with members:
    - "robust secure transmission in miso channels based on worst case optimization"
    - "robust beamforming for security in mimo wiretap channels with imperfect csi"
    - "mimo wiretap channels with arbitrarily varying eavesdropper channel states"
    - "collaborative relay beamforming for secrecy"
    - "secure transmission with multiple antennas ii the mimome wiretap channel"
    - "the secrecy capacity of the mimo wiretap channel"

Connected through hyperedge HE-8 (induced by source paper "strong secrecy and reliable byzantine detection in the presence of an untrusted relay"):
  with members:
    - "a secure communication game with a relay helping the eavesdropper"
    - "the gaussian many to one interference channel with confidential messages"
    - "cooperation with an untrusted relay a secrecy perspective"
    - "the secrecy capacity region of the gaussian mimo multi receiver wiretap channel"
    - "explicit capacity achieving codes for worst case additive errors"
    - "the role of feedback in two way secure communications"
    - "providing secrecy with lattice codes"
    - "an algebraic watchdog for wireless network coding"

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)