human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "implicit smartphone user authentication with sensors and contextual machine learning"):
  Abstract: Authentication of smartphone users is important because a lot of sensitive data is stored in the smartphone and the smartphone is also used to access various cloud data and services. However, smartphones are easily stolen or co-opted by an attacker. Beyond the initial login, it is highly desirable to re-authenticate end-users who are continuing to access security-critical services and data. Hence, this paper proposes a novel authentication system for implicit, continuous authentication of the smartphone user based on behavioral characteristics, by leveraging the sensors already ubiquitously built into smartphones. We propose novel context-based authentication models to differentiate the legitimate smartphone owner versus other users. We systematically show how to achieve high authentication accuracy with different design alternatives in sensor and feature selection, machine learning techniques, context detection and multiple devices. Our system can achieve excellent authentication performance with 98.1% accuracy with negligible system overhead and less than 2.4% battery consumption.

Includes members:
  Member "secure pick up implicit authentication when you start using the smartphone":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "continuous authentication of smartphones based on application usage")
  Member "implicit sensor based authentication of smartphone users with smartwatch":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "secure pick up implicit authentication when you start using the smartphone")
  Member "multi sensor authentication to improve smartphone security":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "sensor based continuous authentication of smartphones users using behavioral biometrics a survey")
  Member "data driven authentication on the effectiveness of user behaviour modelling with mobile device sensors":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "a report on personally identifiable sensor data from smartphone devices")
  Member "touchalytics on the applicability of touchscreen input as a behavioral biometric for continuous authentication":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "on the resilience of biometric authentication systems against random inputs")

Question: Please tell me which class the source paper 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)