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: "private information retrieval in graph based replication systems"
  Abstract: In a Private Information Retrieval (PIR) protocol, a user can download a file from a database without revealing the identity of the file to each individual server. A PIR protocol is called $t$-private if the identity of the file remains concealed even if $t$ of the servers collude. Graph based replication is a simple technique, which is prevalent in both theory and practice, for achieving erasure robustness in storage systems. In this technique each file is replicated on two or more storage servers, giving rise to a (hyper-)graph structure. In this paper we study private information retrieval protocols in graph based replication systems. The main interest of this work is maximizing the parameter $t$, and in particular, understanding the structure of the colluding sets which emerge in a given graph. Our main contribution is a $2$-replication scheme which guarantees perfect privacy from acyclic sets in the graph, and guarantees partial-privacy in the presence of cycles. Furthermore, by providing an upper bound, it is shown that the PIR rate of this scheme is at most a factor of two from its optimal value for an important family of graphs. Lastly, we extend our results to larger replication factors and to graph-based coding, which is a similar technique with smaller storage overhead and larger PIR rate.

Connected through hyperedge HE-1 (induced by source paper "improved storage for efficient private information retrieval"):
  with members:
    - "the capacity of private information retrieval from heterogeneous uncoded caching databases"
    - "staircase pir universally robust private information retrieval"
    - "the capacity of private information retrieval from uncoded storage constrained databases"
    - "private information retrieval from a cellular network with caching at the edge"
    - "cross subspace alignment and the asymptotic capacity of x secure t private information retrieval"
    - "capacity achieving private information retrieval codes with optimal message size and upload cost"
    - "private information retrieval through wiretap channel ii privacy meets security"
    - "the capacity of private information retrieval with private side information under storage constraints"

Connected through hyperedge HE-2 (induced by source paper "on the asymptotic capacity of x secure t private information retrieval with graph based replicated storage"):
  with members:
    - "achievable rate of private function retrieval from mds coded databases"
    - "private information retrieval from coded storage systems with colluding byzantine and unresponsive servers"
    - "cross subspace alignment and the asymptotic capacity of x secure t private information retrieval"
    - "capacity achieving private information retrieval codes with optimal message size and upload cost"
    - "the capacity of private information retrieval with eavesdroppers"
    - "private information retrieval through wiretap channel ii privacy meets security"
    - "asymmetry hurts private information retrieval under asymmetric traffic constraints"
    - "private computation of systematically encoded data with colluding servers"

Connected through hyperedge HE-3 (induced by source paper "private information retrieval from non replicated databases"):
  with members:
    - "the capacity of private information retrieval from heterogeneous uncoded caching databases"
    - "the exact rate memory tradeoff for caching with uncoded prefetching"
    - "staircase pir universally robust private information retrieval"
    - "the capacity of private information retrieval from uncoded storage constrained databases"
    - "private information retrieval from a cellular network with caching at the edge"
    - "private information retrieval from coded storage systems with colluding byzantine and unresponsive servers"
    - "cross subspace alignment and the asymptotic capacity of x secure t private information retrieval"
    - "capacity achieving private information retrieval codes with optimal message size and upload cost"

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)