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 community authorization service for group collaboration"
  Abstract: In "Grids" and "collaboratories," we find distributed communities of resource providers and resource consumers, within which often complex and dynamic policies govern who can use which resources for which purpose. We propose a new approach to the representation, maintenance, and enforcement of such policies that provides a scalable mechanism for specifying and enforcing these policies. Our approach allows resource providers to delegate some of the authority for maintaining fine-grained access control policies to communities, while still maintaining ultimate control over their resources. We also describe a prototype implementation of this approach and an application in a data management context.

Connected through hyperedge HE-1 (induced by source paper "grid security and integration with minimal performance degradation"):
  with members:
    - "security for grid services"
    - "the anatomy of the grid enabling scalable virtual organizations"

Connected through hyperedge HE-2 (induced by source paper "cloud computing and grid computing 360 degree compared"):
  with members:
    - "accelerating large scale data exploration through data diffusion"
    - "the community authorization service status and future"
    - "mpich g2 a grid enabled implementation of the message passing interface"
    - "the anatomy of the grid enabling scalable virtual organizations"
    - "nimrod g an architecture for a resource management and scheduling system in a global computational grid"

Connected through hyperedge HE-3 (induced by source paper "the earth system grid supporting the next generation of climate modeling research"):
  with members:
    - "security for grid services"

Connected through hyperedge HE-4 (induced by source paper "fine grain authorization for resource management in the grid environment"):
  with members:
    - "computational grids in action the natinal fusion collaboratory"
    - "the anatomy of the grid enabling scalable virtual organizations"

Connected through hyperedge HE-5 (induced by source paper "security for grid services"):
  with members:
    - "the anatomy of the grid enabling scalable virtual organizations"

Connected through hyperedge HE-6 (induced by source paper "sharing a conceptual model of grid resources and services"):
  with members:
    - "r gma first results after deployment"

Connected through hyperedge HE-7 (induced by source paper "using cas to manage role based vo sub groups"):
  with members:
    - "the community authorization service status and future"

Connected through hyperedge HE-8 (induced by source paper "the community authorization service status and future"):
  with members:
    - "the anatomy of the grid enabling scalable virtual organizations"

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.DC(Distributed, Parallel, and Cluster Computing)