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: "securefind secure and privacy preserving object finding via mobile crowdsourcing"
  Abstract: The plummeting cost of Bluetooth tags and the ubiquity of mobile devices are revolutionizing the traditional lost-and-found service. This paper presents SecureFind, a secure and privacy-preserving object-finding system via mobile crowdsourcing. In SecureFind, a unique Bluetooth tag is attached to every valuable object, and the owner of a lost object submits an object-finding request to many mobile users via the SecureFind service provider. Each mobile user involved searches his vicinity for the lost object on behalf of the object owner who can infer the location of his lost object based on the responses from mobile users. SecureFind is designed to ensure strong object security such that only the object owner can discover the location of his lost object as well as offering strong location privacy to mobile users involved. The high efficacy and efficiency of SecureFind are confirmed by extensive simulations.

Connected through hyperedge HE-1 (induced by source paper "location privacy in cognitive radio networks a survey"):
  with members:
    - "preserving the location privacy of secondary users in cooperative spectrum sensing"
    - "an efficient technique for protecting location privacy of cooperative spectrum sensing users"
    - "lpos location privacy for optimal sensing in cognitive radio networks"
    - "geo indistinguishability differential privacy for location based systems"
    - "security of spectrum learning in cognitive radios"
    - "channel assignment with access contention resolution for cognitive radio networks"
    - "towards practical oblivious ram"
    - "multi agent q learning of channel selection in multi user cognitive radio systems a two by two case"

Connected through hyperedge HE-2 (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"
    - "privacy preserving schemes for ad hoc social networks 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"
    - "the random oracle methodology revisited"

Connected through hyperedge HE-3 (induced by source paper "your actions tell where you are uncovering twitter users in a metropolitan area"):
  with members:
    - "home location identification of twitter users"
    - "geotagging one hundred million twitter accounts with total variation minimization"

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)