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: "pacer network side channel mitigation in the cloud"
  Abstract: An important concern for many Cloud customers is data confidentiality. Of particular concern are potential data leaks via side channels, which arise when mutually untrusted parties contend on resources such as CPUs, caches, and networks. In this paper, we present a principled solution for mitigating side channels that arise from shared network links. Our solution, Pacer, shapes the outbound traffic of a Cloud tenant to make it independent of the tenant's secrets by design. At the same time, Pacer permits traffic variations based on public (non-secret) aspects of the tenants' computation, thus enabling efficient sharing of network resources. Implementing Pacer requires modest changes to the guest OS and the hosting hypervisor, and only minimal changes to guest applications. Experiments show that Pacer allows guests to protect their secrets with overhead close to the minimum possible considering the guest's conditional traffic distribution given public information. For instance, Pacer can hide a requested Wiktionary document in one of two size clusters at an average throughput and bandwidth overhead of 6.8% and 150%, respectively.

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)