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: "verifying security policies using host attributes"
  Abstract: For the formal verification of a network security policy, it is crucial to express the verification goals. These formal goals, called security invariants, should be easy to express for the end user. Focusing on access control and information flow security strategies, this work discovers and proves universal insights about security invariants. This enables secure and convenient auto-completion of host attribute configurations. We demonstrate our results in a civil aviation scenario. All results are machine-verified with the Isabelle/HOL theorem prover.

Connected through hyperedge HE-1 (induced by source paper "agile network access control in the container age"):
  with members:
    - "semantics preserving simplification of real world firewall rule sets"
    - "demonstrating topos theorem prover based synthesis of secure network configurations"
    - "analysis of docker security"
    - "a fast compiler for netkat"
    - "directed security policies a stateful network implementation"
    - "merlin a language for provisioning network resources"

Connected through hyperedge HE-2 (induced by source paper "privacy assessment using static taint analysis tool paper"):
  with members:
    - "demonstrating topos theorem prover based synthesis of secure network configurations"
    - "privacy and data protection by design from policy to engineering"
    - "privacy design strategies"

Connected through hyperedge HE-3 (induced by source paper "demonstrating topos theorem prover based synthesis of secure network configurations"):
  with members:
    - "semantics preserving simplification of real world firewall rule sets"
    - "a fast compiler for netkat"
    - "directed security policies a stateful network implementation"
    - "merlin a language for provisioning network resources"

Connected through hyperedge HE-4 (induced by source paper "semantics preserving simplification of real world firewall rule sets"):
  with members:
    - "directed security policies a stateful network implementation"

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)