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: "on improving security of gpt cryptosystems"
  Abstract: The public key cryptosystem based on rank error correcting codes (the GPT cryptosystem) was proposed in 1991. Use of rank codes in cryptographic applications is advantageous since it is practically impossible to utilize combinatoric decoding. This enabled using public keys of a smaller size. Several attacks against this system were published, including Gibson's attacks and more recently Overbeck's attacks. A few modifications were proposed withstanding Gibson's attack but at least one of them was broken by the stronger attacks by Overbeck. A tool to prevent Overbeck's attack is presented in [12]. In this paper, we apply this approach to other variants of the GPT cryptosystem.

Connected through hyperedge HE-1 (induced by source paper "interleaving loidreau s rank metric cryptosystem"):
  with members:
    - "low rank parity check codes new decoding algorithms and applications to cryptography"
    - "on the security of a loidreau s rank metric code based encryption scheme"
    - "decoding high order interleaved rank metric codes"
    - "on decoding and applications of interleaved goppa codes"
    - "a public key cryptosystem from interleaved goppa codes"
    - "on the genericity of maximum rank distance and gabidulin codes"
    - "repairing the faure loidreau public key cryptosystem"
    - "further generalisations of twisted gabidulin codes"

Connected through hyperedge HE-2 (induced by source paper "polynomial time key recovery attack on the faure loidreau scheme based on gabidulin codes"):
  with members:
    - "improved cryptanalysis of rank metric schemes based on gabidulin codes"
    - "polynomial time attack on wild mceliece over quadratic extensions"
    - "distinguisher based attacks on public key cryptosystems using reed solomon codes"
    - "on the complexity of the rank syndrome decoding problem"
    - "a smart approach for gpt cryptosystem based on rank codes"

Connected through hyperedge HE-3 (induced by source paper "improved cryptanalysis of rank metric schemes based on gabidulin codes"):
  with members:
    - "extension of overbeck s attack for gabidulin based cryptosystems"
    - "on the complexity of the rank syndrome decoding problem"
    - "a smart approach for gpt cryptosystem based on rank codes"

Connected through hyperedge HE-4 (induced by source paper "extension of overbeck s attack for gabidulin based cryptosystems"):
  with members:
    - "new criteria for mrd and gabidulin codes and some rank metric code constructions"
    - "equivalence for rank metric and matrix codes and automorphism groups of gabidulin codes"
    - "bounds on list decoding of rank metric codes"
    - "on the complexity of the rank syndrome decoding problem"
    - "a smart approach for gpt cryptosystem based on rank codes"
    - "fast encoding and decoding of gabidulin codes"

Connected through hyperedge HE-5 (induced by source paper "on the complexity of the rank syndrome decoding problem"):
  with members:
    - "ranksign an efficient signature algorithm based on the rank metric"
    - "on the hardness of the decoding and the minimum distance problems for rank codes"
    - "on the complexity of the generalized minrank problem"
    - "a smart approach for gpt cryptosystem based on rank codes"
    - "properties of codes in rank metric"

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)