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: "spearphone a speech privacy exploit via accelerometer sensed reverberations from smartphone loudspeakers"
  Abstract: In this paper, we build a speech privacy attack that exploits speech reverberations generated from a smartphone's inbuilt loudspeaker captured via a zero-permission motion sensor (accelerometer). We design our attack, called Spearphone2, and demonstrate that speech reverberations from inbuilt loudspeakers, at an appropriate loudness, can impact the accelerometer, leaking sensitive information about the speech. In particular, we show that by exploiting the affected accelerometer readings and carefully selecting feature sets along with off-the-shelf machine learning techniques, Spearphone can successfully perform gender classification (accuracy over 90%) and speaker identification (accuracy over 80%). In addition, we perform speech recognition and speech reconstruction to extract more information about the eavesdropped speech to an extent. Our work brings to light a fundamental design vulnerability in many currently-deployed smartphones, which may put people's speech privacy at risk while using the smartphone in the loudspeaker mode during phone calls, media playback or voice assistant interactions.

Connected through hyperedge HE-1 (induced by source paper "taxonomy and challenges of out of band signal injection attacks and defenses"):
  with members:
    - "understanding the effectiveness of ultrasonic microphone jammer"
    - "a framework for evaluating security in the presence of signal injection attacks"
    - "trick or heat manipulating critical temperature based control systems using rectification attacks"
    - "oops had the silly thing in reverse optical injection attacks in through led status indicators"
    - "signal jamming attacks against communication based train control attack impact and countermeasure"
    - "systematic classification of side channel attacks a case study for mobile devices"
    - "injected and delivered fabricating implicit control over actuation systems by spoofing inertial sensors"
    - "dolphinattack inaudible voice commands"

Connected through hyperedge HE-2 (induced by source paper "kinetic song comprehension deciphering personal listening habits via phone vibrations"):
  with members:
    - "deep convolutional neural networks and data augmentation for environmental sound classification"
    - "data augmentation of wearable sensor data for parkinson s disease monitoring using convolutional neural networks"
    - "we can track you if you take the metro tracking metro riders using accelerometers on smartphones"
    - "touchalytics on the applicability of touchscreen input as a behavioral biometric for continuous authentication"

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)