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: "a colouring protocol for the generalized russian cards problem"
  Abstract: In the generalized Russian cards problem, Alice, Bob and Cath draw $a$, $b$ and $c$ cards, respectively, from a deck of size $a+b+c$. Alice and Bob must then communicate their entire hand to each other, without Cath learning the owner of a single card she does not hold. Unlike many traditional problems in cryptography, however, they are not allowed to encode or hide the messages they exchange from Cath. The problem is then to find methods through which they can achieve this. We propose a general four-step solution based on finite vector spaces, and call it the "colouring protocol", as it involves colourings of lines. #R##N#Our main results show that the colouring protocol may be used to solve the generalized Russian cards problem in cases where $a$ is a power of a prime, $c=O(a^2)$ and $b=O(c^2)$. This improves substantially on the set of parameters for which solutions are known to exist; in particular, it had not been shown previously that the problem could be solved in cases where the eavesdropper has more cards than one of the communicating players.

Connected through hyperedge HE-1 (induced by source paper "quantifying over boolean announcements"):
  with members:
    - "coalition and group announcement logic"
    - "arbitrary arrow update logic with common knowledge is neither re nor co re"
    - "the undecidability of arbitrary arrow update logic"

Connected through hyperedge HE-2 (induced by source paper "perfectly secure data aggregation via shifted projections"):
  with members:
    - "a case study in almost perfect security for unconditionally secure communication"
    - "almost perfect security for the russian cards problem"
    - "additional constructions to solve the generalized russian cards problem using combinatorial designs"
    - "a geometric protocol for cryptography with cards"

Connected through hyperedge HE-3 (induced by source paper "a case study in almost perfect security for unconditionally secure communication"):
  with members:
    - "perfectly secure data aggregation via shifted projections"
    - "additional constructions to solve the generalized russian cards problem using combinatorial designs"
    - "a geometric protocol for cryptography with cards"

Connected through hyperedge HE-4 (induced by source paper "almost perfect security for the russian cards problem"):
  with members:
    - "additional constructions to solve the generalized russian cards problem using combinatorial designs"
    - "a geometric protocol for cryptography with cards"

Connected through hyperedge HE-5 (induced by source paper "additional constructions to solve the generalized russian cards problem using combinatorial designs"):
  with members:
    - "a geometric protocol for cryptography with cards"
    - "lower bound for the communication complexity of the russian cards problem"

Connected through hyperedge HE-6 (induced by source paper "secure aggregation of distributed information how a team of agents can safely share secrets in front of a spy"):
  with members:
    - "additional constructions to solve the generalized russian cards problem using combinatorial designs"

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)