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: "anonymous and confidential file sharing over untrusted clouds"
  Abstract: Using public cloud services for storing and sharing confidential data requires end users to cryptographically protect both the data and the access to the data. In some cases, the identity of end users needs to remain confidential against the cloud provider and fellow users accessing the data. As such, the underlying cryptographic access control mechanism needs to ensure the anonymity of both data producers and consumers. We introduce A-SKY, a cryptographic access control extension capable of providing confidentiality and anonymity guarantees, all while efficiently scaling to large organizations. A-SKY leverages trusted execution environments (TEEs) to address the impracticality of anonymous broadcast encryption (ANOBE) schemes, achieving faster execution times and shorter ciphertexts. The innovative design of A-SKY limits the usage of the TEE to the narrow set of data producing operations, and thus optimizes the dominant data consumption actions by not requiring a TEE. Furthermore, we propose a scalable implementation for A-SKY leveraging micro-services that preserves strong security guarantees while being able to efficiently manage realistic large user bases. Results highlight that the A-SKY cryptographic scheme is 3 orders of magnitude better than state of the art ANOBE, and an end-to-end system encapsulating A-SKY can elastically scale to support groups of 10 000 users while maintaining processing costs below 1 second.

Connected through hyperedge HE-1 (induced by source paper "distributed systems and trusted execution environments trade offs and challenges"):
  with members:
    - "supply chain malware targets sgx take care of what you sign"
    - "sgx lkl securing the host os interface for trusted execution"
    - "smotherspectre exploiting speculative execution through port contention"
    - "streambox tz secure stream analytics at the edge with trustzone"
    - "sgxpectre stealing intel secrets from sgx enclaves via speculative execution"
    - "cyclosa decentralizing private web search through sgx based browser extensions"
    - "ibbe sgx cryptographic group access control using trusted execution environments"
    - "sgx aware container orchestration for heterogeneous clusters"

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)