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: "authentication and secrecy codes for equiprobable source probability distributions"
  Abstract: We give new combinatorial constructions for codes providing authentication and secrecy for equiprobable source probability distributions. In particular, we construct an infinite class of optimal authentication codes which are multiple-fold secure against spoofing and simultaneously achieve perfect secrecy. Several further new optimal codes satisfying these properties will also be constructed and presented in general tables. Almost all of these appear to be the first authentication codes with these properties.

Connected through hyperedge HE-1 (induced by source paper "disjoint difference families and their applications"):
  with members:
    - "non overlapping codes"
    - "new families of optimal frequency hopping sequence sets"
    - "a combinatorial model of interference in frequency hopping schemes"
    - "high rate self synchronizing codes"
    - "information theoretic authentication and secrecy codes in the splitting model"
    - "combinatorial bounds and characterizations of splitting authentication codes"
    - "strong secrecy and reliable byzantine detection in the presence of an untrusted relay"
    - "optimal rate code constructions for computationally simple channels"

Connected through hyperedge HE-2 (induced by source paper "on an almost universal hash function family with applications to authentication and secrecy codes"):
  with members:
    - "universal hashing for information theoretic security"
    - "exponential decreasing rate of leaked information in universal random privacy amplification"
    - "fuzzy extractors how to generate strong keys from biometrics and other noisy data"

Connected through hyperedge HE-3 (induced by source paper "perfect secrecy systems immune to spoofing attacks"):
  with members:
    - "constructing optimal authentication codes with perfect multi fold secrecy"

Connected through hyperedge HE-4 (induced by source paper "computational complexity of reconstruction and isomorphism testing for designs and line graphs"):
  with members:
    - "reconstructing extended perfect binary one error correcting codes from their minimum distance graphs"

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)