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 d sequence based recursive random number generator"
  Abstract: This paper proposes a new recursive technique using d-sequences to generate random numbers.

Connected through hyperedge HE-1 (induced by source paper "binary random sequences obtained from decimal sequences"):
  with members:
    - "testing kak s conjecture on binary reciprocal of primes and cryptographic applications"
    - "testing d sequences for their randomness"
    - "period of the d sequence based random number generator"
    - "the cubic public key transformation"
    - "watermarking using decimal sequences"

Connected through hyperedge HE-2 (induced by source paper "analysis of prime reciprocal sequences in base 10"):
  with members:
    - "testing kak s conjecture on binary reciprocal of primes and cryptographic applications"
    - "testing d sequences for their randomness"
    - "period of the d sequence based random number generator"
    - "watermarking using decimal sequences"

Connected through hyperedge HE-3 (induced by source paper "partial cross correlation of d sequences based cdma system"):
  with members:
    - "testing d sequences for their randomness"
    - "period of the d sequence based random number generator"
    - "watermarking using decimal sequences"

Connected through hyperedge HE-4 (induced by source paper "period of the d sequence based random number generator"):
  with members:
    - "testing d sequences for their randomness"
    - "the cubic public key transformation"
    - "watermarking using decimal sequences"

Connected through hyperedge HE-5 (induced by source paper "improved watermarking scheme using decimal sequences"):
  with members:
    - "the cubic public key transformation"
    - "watermarking using decimal sequences"

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.CR(Cryptography and Security)