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: "information hiding using improper frame padding"
  Abstract: Hiding information in network traffic may lead to leakage of confidential information. In this paper we introduce a new steganographic system: the PadSteg (Padding Steganography). To authors' best knowledge it is the first information hiding solution which represents interprotocol steganography i.e. usage of relation between two or more protocols from the TCP/IP stack to enable secret communication. PadSteg utilizes ARP and TCP protocols together with an Etherleak vulnerability (improper Ethernet frame padding) to facilitate secret communication for hidden groups in LANs (Local Area Networks). Basing on real network traces we confirm that PadSteg is feasible in today's networks and we estimate what steganographic bandwidth is achievable while limiting the chance of disclosure. We also point at possible countermeasures against PadSteg.

Connected through hyperedge HE-1 (induced by source paper "movesteg a method of network steganography detection"):
  with members:
    - "the good the bad and the ugly evaluation of wi fi steganography"
    - "on steganography in lost audio packets"
    - "using transcoding for hidden communication in ip telephony"

Connected through hyperedge HE-2 (induced by source paper "a pattern based survey and categorization of network covert channel techniques"):
  with members:
    - "steganography using the extensible messaging and presence protocol xmpp"

Connected through hyperedge HE-3 (induced by source paper "towards steganography detection through network traffic visualisation"):
  with members:
    - "steganography of voip streams"

Connected through hyperedge HE-4 (induced by source paper "how hidden can be even more hidden"):
  with members:
    - "padsteg introducing inter protocol steganography"
    - "stream control transmission protocol steganography"
    - "steganography of voip streams"

Connected through hyperedge HE-5 (induced by source paper "padsteg introducing inter protocol steganography"):
  with members:
    - "steganography of voip streams"

Connected through hyperedge HE-6 (induced by source paper "multi level steganography improving hidden communication in networks"):
  with members:
    - "stream control transmission protocol steganography"

Connected through hyperedge HE-7 (induced by source paper "hiding data in ofdm symbols of ieee 802 11 networks"):
  with members:
    - "a performance analysis of hiccups a steganographic system for wlan"

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)