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: "evaluating quality of chaotic pseudo random generators application to information hiding"
  Abstract: Guaranteeing the security of information transmitted through the Internet, against passive or active attacks, is a major concern. The discovery of new pseudo-random number generators with a strong level of security is a field of research in full expansion, due to the fact that numerous cryptosystems and data hiding schemes are directly dependent on the quality of these generators. At the conference Internet`09, we described a generator based on chaotic iterations which behaves chaotically as defined by Devaney. In this paper which is an extension of the work presented at the conference Internet`10, the proposal is to improve the speed, the security, and the evaluation of this generator, to make its use more relevant in the Internet security context. In order to do so, a comparative study between various generators is carried out and statistical results are improved. Finally, an application in the information hiding framework is presented with details, to give an illustrative example of the use of such a generator in the Internet security field.

Connected through hyperedge HE-1 (induced by source paper "lyapunov exponent evaluation of the cbc mode of operation"):
  with members:
    - "hash functions using chaotic iterations"
    - "topological chaos and chaotic iterations application to hash functions"

Connected through hyperedge HE-2 (induced by source paper "fpga design for pseudorandom number generator based on chaotic iteration used in information hiding application"):
  with members:
    - "hash functions using chaotic iterations"
    - "an optimization technique on pseudorandom generators based on chaotic iterations"
    - "a new chaos based watermarking algorithm"
    - "steganography a class of secure and robust algorithms"
    - "topological chaos and chaotic iterations application to hash functions"
    - "chaotic iterations versus spread spectrum chaos and stego security"

Connected through hyperedge HE-3 (induced by source paper "the dynamics of the cbc mode of operation"):
  with members:
    - "hash functions using chaotic iterations"
    - "quantitative evaluation of chaotic cbc mode of operation"
    - "efficient and cryptographically secure generation of chaotic pseudorandom numbers on gpu"

Connected through hyperedge HE-4 (induced by source paper "proving chaotic behavior of cbc mode of operation"):
  with members:
    - "hash functions using chaotic iterations"
    - "efficient and cryptographically secure generation of chaotic pseudorandom numbers on gpu"

Connected through hyperedge HE-5 (induced by source paper "quantitative evaluation of chaotic cbc mode of operation"):
  with members:
    - "hash functions using chaotic iterations"
    - "efficient and cryptographically secure generation of chaotic pseudorandom numbers on gpu"

Connected through hyperedge HE-6 (induced by source paper "the metadata anonymization toolkit"):
  with members:
    - "class of trustworthy pseudo random number generators"

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)