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: "deducing security goals from shape analysis sentences"
  Abstract: Guttman presented a model-theoretic approach to establishing security goals in the context of strand space theory. In his approach, a run of the Cryptographic Protocol Shapes Analyzer (cpsa) produces models that determine if a goal is satised. This paper presents a method for extracting a sentence that completely characterizes a run of cpsa. Logical deduction can then be used to determine if a goal is satised. This method has been implemented and is available to all.

Connected through hyperedge HE-1 (induced by source paper "enrich by need protocol analysis for diffie hellman extended version"):
  with members:
    - "formal support for standardizing protocols with state"

Connected through hyperedge HE-2 (induced by source paper "a hybrid analysis for security protocols with state"):
  with members:
    - "proving security goals with shape analysis sentences"

Connected through hyperedge HE-3 (induced by source paper "proving security goals with shape analysis sentences"):
  with members:
    - "security theorems via model theory"

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)