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: "privacy preserving schemes for ad hoc social networks a survey"
  Abstract: In this paper, we review the state of the art of privacy-preserving schemes for ad hoc social networks, including, mobile social networks (MSNs) and vehicular social networks (VSNs). Specifically, we select and in-detail examine thirty-three privacy preserving schemes developed for or applied in the context of ad hoc social networks. These schemes are published between 2008 and 2016. Based on this existing privacy preservation schemes, we survey privacy preservation models, including location privacy, identity privacy, anonymity, traceability, interest privacy, backward privacy, and content oriented privacy. The recent important attacks of leaking privacy, countermeasures, and game theoretic approaches in VSNs and MSNs are summarized in form of tables. In addition, an overview of recommendations for further research is also provided. With this survey, readers can have a more thorough understanding of research trends in privacy-preserving schemes for ad hoc social networks

Connected through hyperedge HE-1 (induced by source paper "socially aware congestion control in ad hoc networks current status and the way forward"):
  with members:
    - "smartphone based vehicle telematics a ten year anniversary"
    - "socially aware networking a survey"
    - "antnet distributed stigmergetic control for communications networks"

Connected through hyperedge HE-2 (induced by source paper "a survey on the security of pervasive online social networks posns"):
  with members:
    - "a framework for mitigating zero day attacks in iot"
    - "nhad neuro fuzzy based horizontal anomaly detection in online social networks"
    - "self enforcing game theory based resource allocation for lorawan assisted public safety communications"
    - "managing service heterogeneity using osmotic computing"
    - "netspam a network based spam detection framework for reviews in online social media"
    - "a privacy preserving community based p2p osns using broadcast encryption supporting recommendation mechanism"
    - "extension of mih to support fpmipv6 for optimized heterogeneous handover"
    - "analyzing resilience of interest based social networks against node and link failures"

Connected through hyperedge HE-3 (induced by source paper "authentication schemes for smart mobile devices threat models countermeasures and open research issues"):
  with members:
    - "systematic classification of side channel attacks a case study for mobile devices"
    - "active authentication on mobile devices via stylometry application usage web browsing and gps location"
    - "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"

Connected through hyperedge HE-4 (induced by source paper "internet of cloud security and privacy issues"):
  with members:
    - "a survey on privacy preserving schemes for smart grid communications"
    - "combining ensemble methods and social network metrics for improving accuracy of ocsvm on intrusion detection in scada systems"
    - "internet of things iot a vision architectural elements and future directions"
    - "compute and storage clouds using wide area high performance networks"
    - "cloud computing and grid computing 360 degree compared"

Connected through hyperedge HE-5 (induced by source paper "security for 4g and 5g cellular networks a survey of existing authentication and privacy preserving schemes"):
  with members:
    - "cloudifying the 3gpp ip multimedia subsystem for 4g and beyond a survey"
    - "device to device communication in cellular networks"
    - "user association in 5g networks a survey and an outlook"
    - "a survey of downlink non orthogonal multiple access for 5g wireless communication networks"
    - "survey of promising technologies for 5g networks"
    - "assessment of lte wireless access for monitoring of energy distribution in the smart grid"
    - "securefind secure and privacy preserving object finding via mobile crowdsourcing"
    - "the random oracle methodology revisited"

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)