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: "optimization of the parity check matrix density in qc ldpc code based mceliece cryptosystems"
  Abstract: Low-density parity-check (LDPC) codes are one of the most promising families of codes to replace the Goppa codes originally used in the McEliece cryptosystem. In fact, it has been shown that by using quasi-cyclic low-density parity-check (QC-LDPC) codes in this system, drastic reductions in the public key size can be achieved, while maintaining fixed security levels. Recently, some proposals have appeared in the literature using codes with denser parity-check matrices, named moderate-density parity-check (MDPC) codes. However, the density of the parity-check matrices to be used in QC-LDPC code-based variants of the McEliece cryptosystem has never been optimized. This paper aims at filling such gap, by proposing a procedure for selecting the density of the private parity-check matrix, based on the security level and the decryption complexity. We provide some examples of the system parameters obtained through the proposed technique.

Connected through hyperedge HE-1 (induced by source paper "protograph based decoding of ldpc codes with hamming weight amplifiers"):
  with members:
    - "on decoding schemes for the mdpc mceliece cryptosystem"
    - "analysis and design of binary message passing decoders"
    - "cryptanalysis of two mceliece cryptosystems based on quasi cyclic codes"

Connected through hyperedge HE-2 (induced by source paper "ledakem a post quantum key encapsulation mechanism based on qc ldpc codes"):
  with members:
    - "quantum information set decoding algorithms"
    - "worst case qc mdpc decoder for mceliece cryptosystem"
    - "security and complexity of the mceliece cryptosystem based on quasi cyclic low density parity check codes"
    - "enhanced public key security for the mceliece cryptosystem"
    - "cryptanalysis of two mceliece cryptosystems based on quasi cyclic codes"

Connected through hyperedge HE-3 (induced by source paper "design and implementation of a digital signature scheme based on low density generator matrix codes"):
  with members:
    - "using ldgm codes and sparse syndromes to achieve digital signatures"

Connected through hyperedge HE-4 (induced by source paper "a joint encryption encoding scheme using qc ldpc codes based on finite geometry"):
  with members:
    - "improving the efficiency of the ldpc code based mceliece cryptosystem through irregular codes"
    - "sosemanuk a fast software oriented stream cipher"

Connected through hyperedge HE-5 (induced by source paper "soft mceliece mdpc code based mceliece cryptosystems with very compact keys through real valued intentional errors"):
  with members:
    - "security and complexity of the mceliece cryptosystem based on quasi cyclic low density parity check codes"
    - "improving the efficiency of the ldpc code based mceliece cryptosystem through irregular codes"
    - "scaling efficient code based cryptosystems for embedded platforms"
    - "on a family of circulant matrices for quasi cyclic low density generator matrix codes"

Connected through hyperedge HE-6 (induced by source paper "improving the efficiency of the ldpc code based mceliece cryptosystem through irregular codes"):
  with members:
    - "security and complexity of the mceliece cryptosystem based on quasi cyclic low density parity check codes"
    - "coding with scrambling concatenation and harq for the awgn wire tap channel a security gap analysis"
    - "interleaved product ldpc codes"
    - "progressive differences convolutional low density parity check codes"
    - "scaling efficient code based cryptosystems for embedded platforms"
    - "on a family of circulant matrices for quasi cyclic low density generator matrix codes"
    - "construction of near optimum burst erasure correcting low density parity check codes"

Connected through hyperedge HE-7 (induced by source paper "using ldgm codes and sparse syndromes to achieve digital signatures"):
  with members:
    - "security and complexity of the mceliece cryptosystem based on quasi cyclic low density parity check codes"
    - "enhanced public key security for the mceliece cryptosystem"
    - "on a family of circulant matrices for quasi cyclic low density generator matrix codes"

Connected through hyperedge HE-8 (induced by source paper "enhanced public key security for the mceliece cryptosystem"):
  with members:
    - "security and complexity of the mceliece cryptosystem based on quasi cyclic low density parity check codes"
    - "distinguisher based attacks on public key cryptosystems using reed solomon codes"
    - "an efficient cca2 secure variant of the mceliece cryptosystem in the standard model"
    - "improving the efficiency of the ldpc code based mceliece cryptosystem through irregular codes"
    - "a distinguisher based attack on a variant of mceliece s cryptosystem based on reed solomon codes"
    - "a cca2 secure variant of the mceliece cryptosystem"
    - "error correcting pairs for a public key cryptosystem"
    - "on the decoding complexity of cyclic codes up to the bch bound"

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)