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 "on kljn based secure key distribution in vehicular communication networks"):
  Abstract: In a former paper [Fluct. Noise Lett. 13 (2014) 1450020] we introduced a vehicular communication system with unconditionally secure key exchange based on the Kirchhoff-Law–Johnson-Noise (KLJN) key distribution scheme. In this paper, we address the secure KLJN key donation to vehicles. This KLJN key donation solution is performed lane-by-lane by using roadside key provider equipment embedded in the pavement. A method to compute the lifetime of the KLJN key is also given. This key lifetime depends on the car density and gives an upper limit of the lifetime of the KLJN key for vehicular communication networks.

Includes members:
  Member "enhanced usage of keys obtained by physical unconditionally secure distributions":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "current injection attack against the kljn secure key exchange")
  Member "current and voltage based bit errors and their combined mitigation for the kirchhoff law johnson noise secure key exchange":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "random resistor random temperature kirchhoff law johnson noise rrrt kljn key exchange")
  Member "on the security of the kirchhoff law johnson noise kljn communicator":
    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 "securing vehicle communication systems by the kljn key exchange protocol":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "generalized dc loop current attack against the kljn secure key exchange scheme")
  Member "information theoretically secure enhanced johnson noise based key distribution over the smart grid with switched filters":
    also connected through other hyperedges:
      - Hyperedge HE-5 (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-6 (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-7 (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-8 (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)