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: "the applied pi calculus mobile values new names and secure communication"
  Abstract: We study the interaction of the programming construct "new", which generates statically scoped names, with communication via messages on channels. This interaction is crucial in security protocols, which are the main motivating examples for our work, it also appears in other programming-language contexts. #R##N#We define the applied pi calculus, a simple, general extension of the pi calculus in which values can be formed from names via the application of built-in functions, subject to equations, and be sent as messages. (In contrast, the pure pi calculus lacks built-in functions, its only messages are atomic names.) We develop semantics and proof techniques for this extended language and apply them in reasoning about security protocols. #R##N#This paper essentially subsumes the conference paper that introduced the applied pi calculus in 2001. It fills gaps, incorporates improvements, and further explains and studies the applied pi calculus. Since 2001, the applied pi calculus has been the basis for much further work, described in many research publications and sometimes embodied in useful software, such as the tool ProVerif, which relies on the applied pi calculus to support the specification and automatic analysis of security protocols. Although this paper does not aim to be a complete review of the subject, it benefits from that further work and provides better foundations for some of it. In particular, the applied pi calculus has evolved through its implementation in ProVerif, and the present definition reflects that evolution.

Connected through hyperedge HE-1 (induced by source paper "discovering epassport vulnerabilities using bisimilarity"):
  with members:
    - "a method for unbounded verification of privacy type properties"
    - "a proof theoretic analysis of intruder theories"

Connected through hyperedge HE-2 (induced by source paper "journey beyond full abstraction exploring robust property preservation for secure compilation"):
  with members:
    - "when good components go bad formally secure compilation despite dynamic compromise"
    - "a reduced semantics for deciding trace equivalence"
    - "beyond good and evil formalizing the security guarantees of compartmentalizing compilation"
    - "a survey of symbolic methods for establishing equivalence based properties in cryptographic protocols"

Connected through hyperedge HE-3 (induced by source paper "the 5g aka authentication protocol privacy"):
  with members:
    - "formal analysis of 5g authentication"
    - "formal computational unlinkability proofs of rfid protocols"
    - "practical attacks against privacy and availability in 4g lte mobile communication systems"

Connected through hyperedge HE-4 (induced by source paper "context free session types for applied pi calculus"):
  with members:
    - "psi calculi a framework for mobile processes with nominal data and logic"

Connected through hyperedge HE-5 (induced by source paper "analysing and patching speke in iso iec"):
  with members:
    - "automatic verification of correspondences for security protocols"

Connected through hyperedge HE-6 (induced by source paper "a characterisation of open bisimulation using an intuitionistic modal logic"):
  with members:
    - "modal logics for nominal transition systems"
    - "a bisimilarity congruence for the applied pi calculus sufficiently coarse to verify privacy properties"
    - "generating witness of non bisimilarity for the pi calculus"
    - "a two level logic approach to reasoning about computations"
    - "the bedwyr system for model checking over syntactic expressions"

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)