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 "an application of group theory in confidential network communications"):
  Abstract: A new proposal for group key exchange is introduced which proves to be both efficient and secure and compares favorably with state of the art protocols.

Includes members:
  Member "an active attack on a distributed group key exchange system":
    also connected through other hyperedges:
      (none)
  Member "group key management based on semigroup actions":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "on the algebraic structure of e_p m and applications to cryptography")
  Member "an active attack on a multiparty key exchange protocol":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "group key management based on semigroup actions")
  Member "public key cryptography based on semigroup actions":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "on the algebraic structure of e_p m and applications to cryptography")

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.IT(Information Theory)