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: "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.

Connected through hyperedge HE-1 (induced by source paper "generalized dc loop current attack against the kljn secure key exchange scheme"):
  with members:
    - "random resistor random temperature kirchhoff law johnson noise rrrt kljn key exchange"
    - "unconditionally secure credit debit card chip scheme and physical unclonable function"
    - "comments on a new transient attack on the kish key distribution system"
    - "current injection attack against the kljn secure key exchange"
    - "analysis of an attenuator artifact in an experimental attack by gunn allison abbott against the kirchhoff law johnson noise kljn secure key exchange system"
    - "generalized kirchhoff law johnson noise kljn secure key exchange system using arbitrary resistors"
    - "cable capacitance attack against the kljn secure key exchange"
    - "on the security of the kirchhoff law johnson noise kljn communicator"

Connected through hyperedge HE-2 (induced by source paper "a static loop current attack against the kljn secure key exchange system"):
  with members:
    - "random resistor random temperature kirchhoff law johnson noise rrrt kljn key exchange"
    - "unconditionally secure credit debit card chip scheme and physical unclonable function"
    - "comments on a new transient attack on the kish key distribution system"
    - "current injection attack against the kljn secure key exchange"
    - "analysis of an attenuator artifact in an experimental attack by gunn allison abbott against the kirchhoff law johnson noise kljn secure key exchange system"
    - "generalized kirchhoff law johnson noise kljn secure key exchange system using arbitrary resistors"
    - "securing vehicle communication systems by the kljn key exchange protocol"
    - "elimination of a second law attack and all cable resistance based attacks in the kirchhoff law johnson noise kljn secure key exchange system"

Connected through hyperedge HE-3 (induced by source paper "current injection attack against the kljn secure key exchange"):
  with members:
    - "random resistor random temperature kirchhoff law johnson noise rrrt kljn key exchange"
    - "comments on a new transient attack on the kish key distribution system"
    - "resource requirements and speed versus geometry of unconditionally secure physical key exchanges"
    - "key exchange trust evaluation in peer to peer sensor networks with unconditionally secure key exchange"
    - "analysis of an attenuator artifact in an experimental attack by gunn allison abbott against the kirchhoff law johnson noise kljn secure key exchange system"
    - "generalized kirchhoff law johnson noise kljn secure key exchange system using arbitrary resistors"
    - "cable capacitance attack against the kljn secure key exchange"
    - "enhanced usage of keys obtained by physical unconditionally secure distributions"

Connected through hyperedge HE-4 (induced by source paper "resource requirements and speed versus geometry of unconditionally secure physical key exchanges"):
  with members:
    - "analysis of an attenuator artifact in an experimental attack by gunn allison abbott against the kirchhoff law johnson noise kljn secure key exchange system"
    - "what kind of noise guarantees security for the kirchhoff law johnson noise key exchange"
    - "on the security of the kirchhoff law johnson noise kljn communicator"
    - "securing vehicle communication systems by the kljn key exchange protocol"
    - "noise properties in the ideal kirchhoff law johnson noise secure communication system"
    - "on the cracking scheme in the paper a directional coupler attack against the kish key distribution system by gunn allison and abbott"
    - "elimination of a second law attack and all cable resistance based attacks in the kirchhoff law johnson noise kljn secure key exchange system"
    - "do electromagnetic waves exist in a short cable at low frequencies what does physics say"

Connected through hyperedge HE-5 (induced by source paper "key exchange trust evaluation in peer to peer sensor networks with unconditionally secure key exchange"):
  with members:
    - "resource requirements and speed versus geometry of unconditionally secure physical key exchanges"
    - "analysis of an attenuator artifact in an experimental attack by gunn allison abbott against the kirchhoff law johnson noise kljn secure key exchange system"
    - "enhanced usage of keys obtained by physical unconditionally secure distributions"
    - "what kind of noise guarantees security for the kirchhoff law johnson noise key exchange"
    - "on the security of the kirchhoff law johnson noise kljn communicator"
    - "securing vehicle communication systems by the kljn key exchange protocol"
    - "noise properties in the ideal kirchhoff law johnson noise secure communication system"
    - "on the cracking scheme in the paper a directional coupler attack against the kish key distribution system by gunn allison and abbott"

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)