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 distributed trust management framework for detecting malicious packet dropping nodes in a mobile ad hoc network"
  Abstract: In a multi-hop mobile ad hoc network (MANET) mobile nodes communicate with each other forming a cooperative radio network. Security remains a major challenge for these networks due to their features of open medium, dynamically changing topologies, reliance on cooperative algorithms, absence of centralized monitoring points, and lack of any clear lines of defense. Most of the currently existing security algorithms designed for these networks are insecure, in efficient, and have low detection accuracy for nodes’ misbehaviour. In this paper, a new approach has been proposed to bring out the complementary relationship between key distribution and misbehaviour detection for developing an integrated security solution for MANETs. The redundancy of routing information in ad hoc networks is utilized to develop a highly reliable protocol that works even in presence of transient network partitioning and Byzantine failure of nodes. The proposed mechanism is fully co-operative, and thus it is more robust as the vulnerabilities of the election algorithms used for choosing the subset of nodes for cooperation are absent. Simulation results show the effectiveness of the proposed protocol.

Connected through hyperedge HE-1 (induced by source paper "security and privacy issues in wireless mesh networks a survey"):
  with members:
    - "secure and privacy preserving authentication protocols for wireless mesh networks"
    - "reputation and trust based systems for wireless self organizing networks"
    - "secure and privacy aware searching in peer to peer networks"
    - "an efficient and user privacy preserving routing protocol for wireless mesh networks"
    - "a distributed protocol for detection of packet dropping attack in mobile ad hoc networks"
    - "cross layer protocols for multimedia communications over wireless networks"
    - "secure routing in wireless mesh networks"
    - "a survey on wireless sensor network security"

Connected through hyperedge HE-2 (induced by source paper "security in wireless sensor networks"):
  with members:
    - "a mechanism for detection of gray hole attack in mobile ad hoc networks"
    - "secure and privacy aware searching in peer to peer networks"
    - "an efficient and user privacy preserving routing protocol for wireless mesh networks"
    - "a distributed protocol for detection of packet dropping attack in mobile ad hoc networks"
    - "a robust and secure aggregation protocol for wireless sensor networks"
    - "a distributed trust and reputation framework for mobile ad hoc networks"
    - "medians and beyond new aggregation techniques for sensor networks"

Connected through hyperedge HE-3 (induced by source paper "security and privacy issues in cloud computing"):
  with members:
    - "a novel mechanism for detection of distributed denial of service attacks"
    - "a robust mechanism for defending distributed denial of service attacks on web servers"
    - "an agent based intrusion detection system for local area networks"
    - "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.CR(Cryptography and Security)