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: "steganography and steganalysis different approaches"
  Abstract: Steganography is the technique of hiding confidential information within any media. Steganography is often confused with cryptography because the two are similar in the way that they both are used to protect confidential information. The difference between the two is in the appearance in the processed output; the output of steganography operation is not apparently visible but in cryptography the output is scrambled so that it can draw attention. Steganlysis is process to detect of presence of steganography. In this article we have tried to elucidate the different approaches towards implementation of steganography using 'multimedia' file (text, static image, audio and video) and Network IP datagram as cover. Also some methods of steganalysis will be discussed.

Connected through hyperedge HE-1 (induced by source paper "steganalysis detecting lsb steganographic techniques"):
  with members:
    - "reversible and irreversible data hiding technique"
    - "a survey on various data hiding techniques and their comparative analysis"
    - "data hiding techniques using prime and natural numbers"
    - "an lsb data hiding technique using prime numbers"
    - "an lsb data hiding technique using natural number decomposition"

Connected through hyperedge HE-2 (induced by source paper "study of encryption and decryption of wave file in image formats"):
  with members:
    - "rism reputation based intrusion detection system for mobile ad hoc networks"
    - "ant colony based routing for mobile ad hoc networks towards improved quality of services"
    - "a new trusted and collaborative agent based approach for ensuring cloud security"
    - "data hiding techniques using prime and natural numbers"
    - "a semi distributed reputation based intrusion detection system for mobile adhoc networks"
    - "an lsb data hiding technique using natural number decomposition"

Connected through hyperedge HE-3 (induced by source paper "classification of various security techniques in databases and their comparative analysis"):
  with members:
    - "data hiding techniques using prime and natural numbers"
    - "an lsb data hiding technique using prime numbers"
    - "a security protocol for multi user authentication"
    - "an lsb data hiding technique using natural number decomposition"

Connected through hyperedge HE-4 (induced by source paper "a hybrid approach towards intrusion detection based on artificial immune system and soft computing"):
  with members:
    - "detection and prevention of botnets and malware in an enterprise network"
    - "a multi factor security protocol for wireless payment secure web authentication using mobile devices"
    - "an lsb data hiding technique using prime numbers"
    - "a semi distributed reputation based intrusion detection system for mobile adhoc networks"

Connected through hyperedge HE-5 (induced by source paper "a survey on various data hiding techniques and their comparative analysis"):
  with members:
    - "an lsb data hiding technique using prime numbers"
    - "steganography of voip streams"

Connected through hyperedge HE-6 (induced by source paper "fugeids fuzzy genetic paradigms in intrusion detection systems"):
  with members:
    - "a multi factor security protocol for wireless payment secure web authentication using mobile devices"
    - "security scheme for distributed dos in mobile ad hoc networks"

Connected through hyperedge HE-7 (induced by source paper "a paxos based state machine replication system for anomaly detection"):
  with members:
    - "an lsb data hiding technique using prime numbers"
    - "an lsb data hiding technique using natural number decomposition"

Connected through hyperedge HE-8 (induced by source paper "data hiding techniques using number decompositions"):
  with members:
    - "an lsb data hiding technique using prime numbers"

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)