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: "a survey on behavioral biometric authentication on smartphones"
  Abstract: Abstract   Recent research has shown the possibility of using smartphones’ sensors and accessories to extract some behavioral attributes such as touch dynamics, keystroke dynamics and gait recognition. These attributes are known as behavioral biometrics and could be used to verify or identify users implicitly and continuously on smartphones. The authentication systems that have been built based on these behavioral biometric traits are known as active or continuous authentication systems.  This paper provides a review of the active authentication systems. We present the components and the operating process of the active authentication systems in general, followed by an overview of the state-of-the-art behavioral biometric traits that used to develop an active authentication systems and their evaluation on smartphones. We discuss the issues, strengths and limitations that associated with each behavioral biometric trait. Also, we introduce a comparative summary between them. Finally, challenges and open research problems are presented in this research field.

Connected through hyperedge HE-1 (induced by source paper "authentication and authorization for mobile iot devices using bio features recent advances and future trends"):
  with members:
    - "blockchain technologies for the internet of things research issues and challenges"
    - "multimodal biometric authentication using choquet integral and genetic algorithm"
    - "deep learning based dynamic watermarking for secure signal authentication in the internet of things"
    - "partial face detection for continuous authentication"
    - "hmog new behavioral biometric features for continuous authentication of smartphone users"
    - "touchin sightless two factor authentication on multi touch mobile devices"
    - "touchalytics on the applicability of touchscreen input as a behavioral biometric for continuous authentication"
    - "a survey of biometric keystroke dynamics approaches security and challenges"

Connected through hyperedge HE-2 (induced by source paper "continuous authentication of smartphones based on application usage"):
  with members:
    - "effect of context in swipe gesture based continuous authentication on smartphones"
    - "predicting smartphone battery life based on comprehensive and real time usage data"
    - "active authentication on mobile devices via stylometry application usage web browsing and gps location"
    - "secure pick up implicit authentication when you start using the smartphone"
    - "active user authentication for smartphones a challenge data set and benchmark results"
    - "path person authentication using trace histories"
    - "learning human identity from motion patterns"
    - "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)