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: "search me if you can privacy preserving location query service"
  Abstract: Location-Based Service (LBS) becomes increasingly popular with the dramatic growth of smartphones and social network services (SNS), and its context-rich functionalities attract considerable users. Many LBS providers use users' location information to offer them convenience and useful functions. However, the LBS could greatly breach personal privacy because location itself contains much information. Hence, preserving location privacy while achieving utility from it is still an challenging question now. This paper tackles this non-trivial challenge by designing a suite of novel fine-grained Privacy-preserving Location Query Protocol (PLQP). Our protocol allows different levels of location query on encrypted location information for different users, and it is efficient enough to be applied in mobile platforms.

Connected through hyperedge HE-1 (induced by source paper "computationally recoverable camouflage a universal model for privacy aware location based services"):
  with members:
    - "attribute based multi dimensional scalable access control for social media sharing"

Connected through hyperedge HE-2 (induced by source paper "privately information sharing with delusive paths for data forwarding in vehicular networks"):
  with members:
    - "optimal geo indistinguishable mechanisms for location privacy"
    - "improving data forwarding in mobile social networks with infrastructure support a space crossing community approach"

Connected through hyperedge HE-3 (induced by source paper "pps privacy preserving strategyproof social efficient spectrum auction mechanisms"):
  with members:
    - "privacy preserving cloud data access with multi authorities"
    - "privacy preserving data aggregation without secure channel multivariate polynomial evaluation"

Connected through hyperedge HE-4 (induced by source paper "privacy preserving data aggregation without secure channel multivariate polynomial evaluation"):
  with members:
    - "privacy preserving cloud data access with multi authorities"
    - "privacy preserving k secure sum protocol"

Connected through hyperedge HE-5 (induced by source paper "privacy preserving cloud data access with multi authorities"):
  with members:
    - "message in a sealed bottle privacy preserving friending in social networks"

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)