human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "noise properties in the ideal kirchhoff law johnson noise secure communication system"):
  Abstract: In this paper we determine the noise properties needed for unconditional security for the ideal Kirchhoff-Law-Johnson-Noise (KLJN) secure key distribution system using simple statistical analysis. It has already been shown using physical laws that resistors and Johnson-like noise sources provide unconditional security. However real implementations use artificial noise generators, therefore it is a question if other kind of noise sources and resistor values could be used as well. We answer this question and in the same time we provide a theoretical basis to analyze real systems as well.

Includes members:
  Member "information theoretically secure enhanced johnson noise based key distribution over the smart grid with switched filters":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "generalized dc loop current attack against the kljn secure key exchange scheme")
  Member "errors and their mitigation at the kirchhoff law johnson noise secure key exchange":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "a static loop current attack against the kljn secure key exchange system")
  Member "enhanced secure key exchange systems based on the johnson noise scheme":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "generalized dc loop current attack against the kljn secure key exchange scheme")
  Member "critical analysis of the bennett riedel attack on secure cryptographic key distributions via the kirchhoff law johnson noise scheme":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "generalized dc loop current attack against the kljn secure key exchange scheme")

Question: Please tell me which class the source paper 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)