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: "a novel mechanism for detection of distributed denial of service attacks"
  Abstract: The increasing popularity of web-based applications has led to several critical services being provided over the Internet. This has made it imperative to monitor the network traffic so as to prevent malicious attackers from depleting the resources of the network and denying services to legitimate users. This paper has presented a mechanism for protecting a web-server against a distributed denial of service (DDoS) attack. Incoming traffic to the server is continuously monitored and any abnormal rise in the inbound traffic is immediately detected. The detection algorithm is based on a statistical analysis of the inbound traffic on the server and a robust hypothesis testing framework. While the detection process is on, the sessions from the legitimate sources are not disrupted and the load on the server is restored to the normal level by blocking the traffic from the attacking sources. To cater to different scenarios, the detection algorithm has various modules with varying level of computational and memory overheads for their execution. While the approximate modules are fast in detection and involve less overhead, they have lower detection accuracy. The accurate modules involve complex detection logic and hence involve more overhead for their execution, but they have very high detection accuracy. Simulations carried out on the proposed mechanism have produced results that demonstrate effectiveness of the scheme.

Connected through hyperedge HE-1 (induced by source paper "homomorphic encryption theory and application"):
  with members:
    - "security in wireless sensor networks"
    - "security and privacy issues in wireless mesh networks a survey"
    - "an attack on privacy preserving data aggregation protocol for wireless sensor networks"
    - "secure and privacy preserving data aggregation protocols for wireless sensor networks"
    - "secure and privacy preserving authentication protocols for wireless mesh networks"
    - "a mechanism for detection of gray hole attack in mobile ad hoc networks"
    - "reputation and trust based systems for wireless self organizing networks"
    - "secure and privacy aware searching in peer to peer networks"

Connected through hyperedge HE-2 (induced by source paper "security and privacy issues in cloud computing"):
  with members:
    - "a robust mechanism for defending distributed denial of service attacks on web servers"
    - "an agent based intrusion detection system for local area networks"
    - "a distributed trust management framework for detecting malicious packet dropping nodes in a mobile ad hoc network"
    - "an intrusion detection architecture for clustered wireless ad hoc networks"
    - "a robust and fault tolerant distributed intrusion detection system"
    - "a distributed trust and reputation framework for mobile ad hoc networks"

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.NI(Networking and Internet Architecture)