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: "on secure network coding for two unicast sessions studying butterflies"
  Abstract: This paper considers a class of wireline networks, derived from the well-known butterfly network, over which two independent unicast sessions take place simultaneously. The main objectives are to understand when network coding type of operations are beneficial with and without security considerations and to derive the gains that cooperation among sources and sinks can bring. Towards these goals, the capacity region of the butterfly network with arbitrary edge capacities is first derived. It is then shown that no rate can be guaranteed over this network under security considerations, when an eavesdropper wiretaps any one link. Four variations of the butterfly network, such as the case of co-located sources, are analyzed and their secure and non-secure capacity regions are characterized.

Connected through hyperedge HE-1 (induced by source paper "on secure network coding for multiple unicast traffic"):
  with members:
    - "coding across unicast sessions can increase the secure message capacity"
    - "lp formulations for secrecy over erasure networks with feedback"
    - "secret message capacity of a line network"
    - "on secure network coding with nonuniform or restricted wiretap sets"
    - "the single source two terminal network with network coding"

Connected through hyperedge HE-2 (induced by source paper "secure network code for adaptive and active attacks with no randomness in intermediate nodes"):
  with members:
    - "secrecy and robustness for active attack in secure network coding and its application to network quantum key distribution"
    - "universal secure multiplex network coding with dependent and non uniform messages"
    - "secure multi source multicast"
    - "coding across unicast sessions can increase the secure message capacity"
    - "quantum inspired secure wireless communication protocol under spatial and local gaussian noise assumptions"
    - "secure wireless communication under spatial and local gaussian noise assumptions"
    - "relative generalized rank weight of linear codes and its applications to network coding"
    - "coding against a limited view adversary the effect of causality and feedback"

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.IT(Information Theory)