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 "comparing bb84 and authentication aided kak s three stage quantum protocol"):
  Abstract: This paper compares the popular quantum key distribution (QKD) protocol BB84 with the more recent Kak's three-stage protocol and the latter is shown to be more secure. A theoretical representation of an authentication-aided version of Kak's three-stage protocol is provided that makes it possible to deal with the man-in-the-middle attack.

Includes members:
  Member "trusted certificates in quantum cryptography":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "variations on kak s three stage quantum cryptography protocol")
  Member "implementing the three stage quantum cryptography protocol":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "classical authentication aided three stage quantum protocol")
  Member "classical authentication aided three stage quantum protocol":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "variations on kak s three stage quantum cryptography protocol")

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)