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: "an empirical study of the power consumption of cryptographic primitives in android"
  Abstract: Green computing has become a growing trend in computing, pursuing the goal of helping software developers to pay more attention to produce energy-effiency software. This is specially relevant for battery-powered mobile applications, where minimizing the energy consumption is required to both mitigate the greenhouse effect and to extend the battery lifetime. In this paper we analyze the energy consumption of cryptographic primitives in Android devices. Our ultimate goal is to help Android application developers, especially those who are not experts on security, to choose the most energy efficient cryptographic algorithms considering different security providers and different security transformations. We have performed our experiments using an energy profiling tool based on the PowerTutor application. Our results show that this type of energy efficiency studies are necessary, because selecting the most energy efficient configuration depends on many factors, and some of the conclusions are not so obvious.

Connected through hyperedge HE-1 (induced by source paper "security privacy and safety evaluation of dynamic and static fleets of drones"):
  with members:
    - "serverless protocols for inventory and tracking with a uav"
    - "survey of important issues in uav communication networks"
    - "vbca a virtual forces clustering algorithm for autonomous aerial drone systems"
    - "outdoor flocking and formation flight with autonomous aerial robots"
    - "learning monocular reactive uav control in cluttered natural environments"

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)