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: "error free perfect secrecy systems"
  Abstract: Shannon's fundamental bound for perfect secrecy says that the entropy of the secret message U cannot be larger than the entropy of the secret key R shared by the sender and the legitimate receiver. Massey gave an information theoretic proof of this result and the proof does not require U and R to be independent. By adding an extra assumption that I(U; R) = 0, we show a tighter lower bound on H(R) by proving that the logarithm of the message sample size cannot be larger than the entropy of the secret key. Then we consider that a perfect secrecy system is used multiple times. A new parameter, namely effective key consumption, is defined and justified. This paper shows the existence of a fundamental tradeoff between the effective key consumption and the number of channel uses for transmitting a ciphertext.

Connected through hyperedge HE-1 (induced by source paper "universal hashing for information theoretic security"):
  with members:
    - "secure multiplex coding with dependent and non uniform multiple messages"
    - "equivocations exponents and second order coding rates under various r enyi information measures"
    - "converses for secret key agreement and secure computing"
    - "secret key agreement general capacity and second order asymptotics"
    - "achieving secrecy capacity of the wiretap channel and broadcast channel with a confidential component"
    - "a new upperbound for the oblivious transfer capacity of discrete memoryless channels"
    - "strong converse for a degraded wiretap channel via active hypothesis testing"
    - "semantically secure lattice codes for the gaussian wiretap channel"

Connected through hyperedge HE-2 (induced by source paper "semantically secure coding scheme achieving the capacity of a gaussian wiretap channel"):
  with members:
    - "secure multiplex coding with dependent and non uniform multiple messages"
    - "equivocations exponents and second order coding rates under various r enyi information measures"
    - "converses for secret key agreement and secure computing"
    - "secret key agreement general capacity and second order asymptotics"
    - "a new upperbound for the oblivious transfer capacity of discrete memoryless channels"
    - "the complexity of estimating r enyi entropy"
    - "strong converse for a degraded wiretap channel via active hypothesis testing"
    - "semantically secure lattice codes for the gaussian wiretap channel"

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)