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: "lengthening and extending binary private information retrieval codes"
  Abstract: It was recently shown by Fazeli et al. that the storage overhead of a traditional $t$-server private information retrieval (PIR) protocol can be significantly reduced using the concept of a $t$-server PIR code. In this work, we show that a family of $t$-server PIR codes (with increasing dimensions and blocklengths) can be constructed from an existing $t$-server PIR code through lengthening by a single information symbol and code extension by at most $\bigl\lceil t/2\bigr\rceil$ code symbols. Furthermore, by extending a code construction notion from Steiner systems by Fazeli et al., we obtain a specific family of $t$-server PIR codes. Based on a code construction technique that lengthens and extends a $t$-server PIR code simultaneously, a basic algorithm to find good (i.e., small blocklength) $t$-server PIR codes is proposed. For the special case of $t=5$, we find provably optimal PIR codes for code dimensions $k\leq 6$, while for all $7\leq k\leq 32$ we find codes of smaller blocklength than the best known codes from the literature. Furthermore, in the case of $t = 8$, we also find better codes for $k = 5, 6, 11, 12$. Numerical results show that most of the best found $5$-server PIR codes can be constructed from the proposed family of codes connected to Steiner systems.

Connected through hyperedge HE-1 (induced by source paper "pir codes with short block length"):
  with members:
    - "batch and pir codes and their connections to locally repairable codes"
    - "determining the generalized hamming weight hierarchy of the binary projective reed muller code"
    - "t private information retrieval schemes using transitive codes"
    - "locality via partially lifted codes"
    - "lower bound on the redundancy of pir codes"
    - "pir with low storage overhead coding instead of replication"
    - "achieving arbitrary locality and availability in binary codes"
    - "locality and availability in distributed storage"

Connected through hyperedge HE-2 (induced by source paper "locality and availability of array codes constructed from subspaces"):
  with members:
    - "nearly optimal constructions of pir and batch codes"
    - "binary shortened projective reed muller codes for coded private information retrieval"
    - "locality via partially lifted codes"
    - "pir array codes with optimal virtual server rate"
    - "bounds and constructions of codes with multiple localities"
    - "codes with unequal locality"
    - "on private information retrieval array codes"
    - "lower bound on the redundancy of pir codes"

Connected through hyperedge HE-3 (induced by source paper "nearly optimal constructions of pir and batch codes"):
  with members:
    - "locality via partially lifted codes"
    - "lower bound on the redundancy of pir codes"
    - "pir with low storage overhead coding instead of replication"
    - "bounds for batch codes with restricted query size"
    - "locality and availability in distributed storage"
    - "linear batch codes"
    - "a family of optimal locally recoverable codes"
    - "optimal combinatorial batch codes based on block designs"

Connected through hyperedge HE-4 (induced by source paper "pir schemes with small download complexity and low storage requirements"):
  with members:
    - "a general private information retrieval scheme for mds coded databases with colluding servers"
    - "the capacity of cache aided private information retrieval"
    - "the capacity of private information retrieval from byzantine and colluding databases"
    - "nearly optimal constructions of pir and batch codes"
    - "private information retrieval from mds coded data with colluding servers settling a conjecture by freij hollanti et al"
    - "secure symmetric private information retrieval from colluding databases with adversaries"
    - "private information retrieval with side information"
    - "robust private information retrieval on coded data"

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)