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: "safekeeper protecting web passwords using trusted execution environments"
  Abstract: Passwords are by far the most widely-used mechanism for authenticating users on the web, out-performing all competing solutions in terms of deployability (e.g., cost, compatibility etc.). However, two critical security concerns are phishing and theft of password databases. These are exacerbated by users’ tendency to reuse passwords across different services. Current solutions typically address only one of the two concerns, and do not protect passwords against rogue servers. Furthermore, they do not provide any verifiable evidence of their (server-side) adoption to users, and they face deployability challenges in terms of  ease-of-use for end users, and/or costs for service providers. We present SafeKeeper, a novel and comprehensive solution to ensure secrecy of passwords in web authentication systems. Unlike previous approaches, SafeKeeper protects users’ passwords against very strong adversaries, including external phishers as well as corrupted (rogue) servers. It is relatively inexpensive to deploy as it (i) uses widely available hardware-based trusted execution environments like Intel SGX, (ii) requires only minimal changes for integration into popular web platforms like WordPress, and (iii) imposes negligible performance overhead. We discuss several challenges in designing and implementing such a system, and how we overcome them. Via an 86-participant user study, systematic analysis, and experiments, we show the usability, security, and deployability of SafeKeeper, which is available as open-source.

Connected through hyperedge HE-1 (induced by source paper "keys in the clouds auditable multi device access to cryptographic credentials"):
  with members:
    - "the circle game scalable private membership test using trusted hardware"
    - "intel sgx enabled key manager service with openstack barbican"
    - "inferring fine grained control flow inside sgx enclaves with branch shadowing"

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)