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: "new results for traitor tracing schemes"
  Abstract: In the last two decades, several classes of codes are introduced to protect the copyrighted digital data. They have important applications in the scenarios like digital fingerprinting and broadcast encryption schemes. In this paper we will discuss three important classes of such codes, namely, frameproof codes, parent-identifying codes and traceability codes. #R##N#Firstly, suppose $N(t)$ is the minimal integer such that there exists a binary $t$-frameproof code of length $N$ with cardinality larger than $N$, we prove that $N(t)\ge\frac{15+\sqrt{33}}{24} (t-2)^2$, which is a great improvement of the previously known bound $N(t)\ge\binom{t+1}{2}$. Moreover, we find that the determination of $N(t)$ is closely related to a conjecture of Erd\H{o}s, Frankl and F\"uredi posed in the 1980's, which implies the conjectured value $N(t)=t^2+o(t^2)$. Secondly, we derive a new upper bound for parent-identifying codes, which is superior than all previously known bounds. Thirdly, we present an upper bound for 3-traceability codes, which shows that a $q$-ary 3-traceability code of length $N$ can have at most $cq^{\lceil N/9\rceil}$ codewords, where $c$ is a constant only related to the code length $N$. It is the first meaningful upper bound for 3-traceability codes and our result supports a conjecture of Blackburn et al. posed in 2010.

Connected through hyperedge HE-1 (induced by source paper "some new bounds of placement delivery arrays"):
  with members:
    - "placement delivery array design through strong edge coloring of bipartite graphs"
    - "optimal placement delivery arrays with minimum number of rows"
    - "a new converse bound for coded caching"
    - "fundamental limits of caching improved delivery rate cache capacity trade off"
    - "centralized coded caching schemes a hypergraph theoretical approach"
    - "the optimal placement delivery arrays"
    - "a note on the fundamental limits of coded caching"
    - "hierarchical coded caching"

Connected through hyperedge HE-2 (induced by source paper "bounds on traceability schemes"):
  with members:
    - "separating hash families a johnson type bound and new constructions"
    - "new bounds on the number of tests for disjunct matrices"
    - "new bounds for frameproof codes"

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.IT(Information Theory)