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: "optical exfiltration of data via keyboard led status indicators to ip cameras"
  Abstract: The ability of the light-emitting diodes (LEDs) on a keyboard to send data at a rate that is far greater than the human eye can perceive has been fully studied. However, an IP camera can only fetch high-resolution images at a low frame rate. It is unable to act as a sink of the optical covert channel directly. In this paper, a novel form of modulation is proposed to modulate the LEDs on a keyboard. The modulated signal can be received by a nearby IP camera. To verify its validity, we implement a prototype of exfiltration malware. Our experiment shows a significant improvement in the imperceptibility of covert communication. Against the background of the Internet of Things, it is possible to leak data covertly to IP cameras across air-gapped networks via LED keyboard status indicators.

Connected through hyperedge HE-1 (induced by source paper "data exfiltration via multipurpose rfid cards and countermeasures"):
  with members:
    - "spectre attacks exploiting speculative execution"
    - "xled covert data exfiltration from air gapped networks via router leds"
    - "usbee air gap covert channel via electromagnetic emission from usb"
    - "fansmitter acoustic data exfiltration from speakerless air gapped computers"
    - "on covert acoustical mesh networks in air"
    - "airhopper bridging the air gap between isolated networks and mobile phones using radio frequencies"

Connected through hyperedge HE-2 (induced by source paper "powerhammer exfiltrating data from air gapped computers through power lines"):
  with members:
    - "data exfiltration via multipurpose rfid cards and countermeasures"
    - "optical tempest"
    - "odini escaping sensitive data from faraday caged air gapped computers via magnetic fields"
    - "magneto covert channel between air gapped systems and nearby smartphones via cpu generated magnetic fields"
    - "mosquito covert ultrasonic transmissions between two air gapped computers using speaker to speaker communication"
    - "air jumper covert air gap exfiltration infiltration via security cameras infrared ir"
    - "xled covert data exfiltration from air gapped networks via router leds"
    - "usbee air gap covert channel via electromagnetic emission from usb"

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)