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: "optimal download cost of private information retrieval for arbitrary message length"
  Abstract: A private information retrieval scheme is a mechanism that allows a user to retrieve any one out of $K$ messages from $N$ non-communicating replicated databases, each of which stores all $K$ messages, without revealing anything about the identity of the desired message index to any individual database. If the size of each message is $L$ bits and the total download required by a PIR scheme from all $N$ databases is $D$ bits, then $D$ is called the download cost and the ratio $L/D$ is called an achievable rate. For fixed $K,N\in\mathbb{N}$, the capacity of PIR, denoted by $C$, is the supremum of achievable rates over all PIR schemes and over all message sizes, and was recently shown to be $C=(1+1/N+1/N^2+\cdots+1/N^{K-1})^{-1}$. In this work, for arbitrary $K, N$, we explore the minimum download cost $D_L$ across all PIR schemes (not restricted to linear schemes) for arbitrary message lengths $L$ under arbitrary choices of alphabet (not restricted to finite fields) for the message and download symbols. If the same $M$-ary alphabet is used for the message and download symbols, then we show that the optimal download cost in $M$-ary symbols is $D_L=\lceil\frac{L}{C}\rceil$. If the message symbols are in $M$-ary alphabet and the downloaded symbols are in $M'$-ary alphabet, then we show that the optimal download cost in $M'$-ary symbols, $D_L\in\left\{\left\lceil \frac{L'}{C}\right\rceil,\left\lceil \frac{L'}{C}\right\rceil-1,\left\lceil \frac{L'}{C}\right\rceil-2\right\}$, where $L'= \lceil L \log_{M'} M\rceil$.

Connected through hyperedge HE-1 (induced by source paper "latent variable private information retrieval"):
  with members:
    - "x secure t private information retrieval from mds coded storage with byzantine and unresponsive servers"
    - "the capacity of private information retrieval from heterogeneous uncoded caching databases"
    - "breaking the mds pir capacity barrier via joint storage coding"
    - "robust private information retrieval from coded systems with byzantine and colluding servers"
    - "the capacity of private information retrieval from uncoded storage constrained databases"
    - "an mds pir capacity achieving protocol for distributed storage using non mds linear codes"
    - "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"

Connected through hyperedge HE-2 (induced by source paper "towards practical private information retrieval from mds array codes"):
  with members:
    - "a new capacity achieving private information retrieval scheme with almost optimal file length for coded servers"
    - "on the pir capacity of msr codes"
    - "breaking the mds pir capacity barrier via joint storage coding"
    - "a generic transformation to enable optimal repair in mds codes for distributed storage systems"
    - "capacity achieving private information retrieval codes with optimal message size and upload cost"
    - "private information retrieval from mds coded data in distributed storage systems"
    - "on sub packetization and access number of capacity achieving pir schemes for mds coded non colluding servers"
    - "private information retrieval schemes with regenerating codes"

Connected through hyperedge HE-3 (induced by source paper "towards the capacity of private information retrieval from coded and colluding servers"):
  with members:
    - "on the capacity of private information retrieval from coded colluding and adversarial servers"
    - "lifting private information retrieval from two to any number of messages"
    - "private information retrieval from coded storage systems with colluding byzantine and unresponsive servers"
    - "on the capacity of single server multi message private information retrieval with side information"
    - "capacity of single server single message private information retrieval with coded side information"
    - "the capacity of private information retrieval from byzantine and colluding databases"
    - "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"

Connected through hyperedge HE-4 (induced by source paper "private information retrieval over gaussian mac"):
  with members:
    - "noisy private information retrieval on separability of channel coding and information retrieval"
    - "asymptotically optimal scheduling for compute and forward"
    - "private information retrieval from mds coded data in distributed storage systems"
    - "the capacity of private information retrieval with partially known private side information"
    - "gaussian multiple access via compute and forward"
    - "the capacity of private information retrieval from byzantine and colluding databases"
    - "the necessity of scheduling in compute and forward"
    - "the capacity of robust private information retrieval with colluding databases"

Connected through hyperedge HE-5 (induced by source paper "private set intersection a multi message symmetric private information retrieval perspective"):
  with members:
    - "the capacity of private information retrieval from heterogeneous uncoded caching databases"
    - "on the storage cost of private information retrieval"
    - "on the information leakage in private information retrieval systems"
    - "capacity achieving private information retrieval codes from mds coded databases with minimum message size"
    - "improved storage for efficient private information retrieval"
    - "staircase pir universally robust private information retrieval"
    - "noisy private information retrieval on separability of channel coding and information retrieval"
    - "the capacity of private information retrieval from uncoded storage constrained databases"

Connected through hyperedge HE-6 (induced by source paper "the capacity of private information retrieval from heterogeneous uncoded caching databases"):
  with members:
    - "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"
    - "coded caching for heterogeneous systems an optimization perspective"
    - "capacity achieving private information retrieval codes with optimal message size and upload cost"
    - "converse for multi server single message pir with side information"

Connected through hyperedge HE-7 (induced by source paper "the capacity of multi round private information retrieval from byzantine databases"):
  with members:
    - "staircase pir universally robust private information retrieval"
    - "robust private information retrieval from coded systems with byzantine and colluding servers"
    - "noisy private information retrieval on separability of channel coding and information retrieval"
    - "asymmetry helps improved private information retrieval protocols for distributed storage"
    - "private information retrieval from a cellular network with caching at the edge"
    - "an mds pir capacity achieving protocol for distributed storage using non mds linear codes"
    - "lifting private information retrieval from two to any number of messages"
    - "cross subspace alignment and the asymptotic capacity of x secure t private information retrieval"

Connected through hyperedge HE-8 (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"
    - "private information retrieval in graph based replication systems"
    - "asymmetry hurts private information retrieval under asymmetric traffic constraints"

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)