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: "security policies as membranes in systems for global computing"
  Abstract: We propose a simple global computing framework, whose main concern is code#N#migration. Systems are structured in sites, and each site is divided into two#N#parts: a computing body, and a membrane, which regulates the interactions#N#between the computing body and the external environment. More precisely,#N#membranes are filters which control access to the associated site, and they#N#also rely on the well-established notion of trust between sites. We develop a#N#basic theory to express and enforce security policies via membranes. Initially,#N#these only control the actions incoming agents intend to perform locally. We#N#then adapt the basic theory to encompass more sophisticated policies, where the#N#number of actions an agent wants to perform, and also their order, are#N#considered.

Connected through hyperedge HE-1 (induced by source paper "information flow in a distributed security setting"):
  with members:
    - "very static enforcement of dynamic policies"
    - "the anatomy and facets of dynamic policies"

Connected through hyperedge HE-2 (induced by source paper "a calculus for sensor networks"):
  with members:
    - "network information flow with correlated sources"

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.PL(Programming Languages)