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: "polynomial time solutions of computational problems in noncommutative algebraic cryptography"
  Abstract: We introduce the linear centralizer method, and use it to devise a provable polynomial-time solution of the Commutator Key Exchange Problem, the computational problem on which, in the passive adversary model, the security of the Anshel---Anshel---Goldfeld (Anshel et al., Math. Res. Lett. 6:287---291, 1999) Commutator key exchange protocol is based. We also apply this method to solve, in polynomial time, the computational problem underlying the Centralizer key exchange protocol, introduced by Shpilrain and Ushakov in (Contemp. Math. 418:161---167, 2006).#R##N##R##N#This is the first provable polynomial-time cryptanalysis of the Commutator key exchange protocol, hitherto the most important key exchange protocol in the realm of noncommutative algebraic cryptography, and the first cryptanalysis (of any kind) of the Centralizer key exchange protocol. Unlike earlier cryptanalyses of the Commutator key exchange protocol, our cryptanalyses cannot be foiled by changing the distributions used in the protocol.

Connected through hyperedge HE-1 (induced by source paper "post quantum cryptography pqc generalized elgamal cipher over gf 251 8"):
  with members:
    - "non associative public key cryptography"

Connected through hyperedge HE-2 (induced by source paper "the status of polycyclic group based cryptography a survey and open problems"):
  with members:
    - "a secret sharing scheme based on group presentations and the word problem"
    - "non commutative digital signatures"
    - "zero knowledge authentication schemes from actions on graphs groups or rings"
    - "length based attacks for certain group based encryption rewriting systems"

Connected through hyperedge HE-3 (induced by source paper "non associative key establishment for left distributive systems"):
  with members:
    - "using shifted conjugacy in braid based cryptography"

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)