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: "automatic verification of correspondences for security protocols"
  Abstract: We present a new technique for verifying correspondences in security protocols. In particular, correspondences can be used to formalize authentication. Our technique is fully automatic, it can handle an unbounded number of sessions of the protocol, and it is efficient in practice. It significantly extends a previous technique for the verification of secrecy. The protocol is represented in an extension of the pi calculus with fairly arbitrary cryptographic primitives. This protocol representation includes the specification of the correspondence to be verified, but no other annotation. This representation is then translated into an abstract representation by Horn clauses, which is used to prove the desired correspondence. Our technique has been proved correct and implemented. We have tested it on various protocols from the literature. The experimental results show that these protocols can be verified by our technique in less than 1 s.

Connected through hyperedge HE-1 (induced by source paper "formal analysis of an e health protocol"):
  with members:
    - "an epistemic approach to coercion resistance for electronic voting protocols"

Connected through hyperedge HE-2 (induced by source paper "analysing and patching speke in iso iec"):
  with members:
    - "the applied pi calculus mobile values new names and secure communication"

Connected through hyperedge HE-3 (induced by source paper "the applied pi calculus mobile values new names and secure communication"):
  with members:
    - "a sorted semantic framework for applied process calculi"
    - "psi calculi a framework for mobile processes with nominal data and logic"
    - "yapa a generic tool for computing intruder knowledge"
    - "tulafale a security tool for web services"

Connected through hyperedge HE-4 (induced by source paper "a secure and authenticated key management protocol sa kmp for vehicular networks"):
  with members:
    - "the case for dynamic key distribution for pki based vanets"

Connected through hyperedge HE-5 (induced by source paper "verifying cryptographic security implementations in c using automated model extraction"):
  with members:
    - "guiding a general purpose c verifier to prove cryptographic protocols"
    - "extracting and verifying cryptographic models from c protocol code by symbolic execution"
    - "a formally verified compiler back end"
    - "a static analyzer for large safety critical software"
    - "inductive analysis of the internet protocol tls"

Connected through hyperedge HE-6 (induced by source paper "fatal attractors in parity games building blocks for partial solvers"):
  with members:
    - "zielonka s recursive algorithm dull weak and solitaire games and tighter bounds"
    - "an o n 2 time algorithm for alternating b uchi games"

Connected through hyperedge HE-7 (induced by source paper "extracting and verifying cryptographic models from c protocol code by symbolic execution"):
  with members:
    - "guiding a general purpose c verifier to prove cryptographic protocols"
    - "a formally verified compiler back end"

Connected through hyperedge HE-8 (induced by source paper "satisfiability of general intruder constraints with and without a set constructor"):
  with members:
    - "predicate abstraction with indexed predicates"

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)