human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "keystone an open framework for architecting tees"):
  Abstract: Trusted execution environments (TEEs) are being used in all the devices from embedded sensors to cloud servers and encompass a range of cost, power constraints, and security threat model choices. On the other hand, each of the current vendor-specific TEEs makes a fixed set of trade-offs with little room for customization. We present Keystone -- the first open-source framework for building customized TEEs. Keystone uses simple abstractions provided by the hardware such as memory isolation and a programmable layer underneath untrusted components (e.g., OS). We build reusable TEE core primitives from these abstractions while allowing platform-specific modifications and application features. We showcase how Keystone-based TEEs run on unmodified RISC-V hardware and demonstrate the strengths of our design in terms of security, TCB size, execution of a range of benchmarks, applications, kernels, and deployment models.

Includes members:
  Member "ekiden a platform for confidentiality preserving trustworthy and performant smart contracts":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "on the convergence of artificial intelligence and distributed ledger technology a scoping review and future research agenda")
  Member "zombieload cross privilege boundary data sampling":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "hardware security for and beyond cmos technology an overview on fundamentals applications and challenges")
  Member "practical verifiable in network filtering for ddos defense":
    also connected through other hyperedges:
      (none)
  Member "sanctorum a lightweight security monitor for secure enclaves":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "ironhide a secure multicore architecture that leverages hardware isolation against microarchitecture state attacks")
  Member "spectre attacks exploiting speculative execution":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "towards probabilistic verification of machine unlearning")
  Member "besfs mechanized proof of an iago safe filesystem for enclaves":
    also connected through other hyperedges:
      (none)
  Member "privado practical and secure dnn inference":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "mind your weight s a large scale study on insufficient machine learning model protection in mobile apps")
  Member "mi6 secure enclaves in a speculative out of order processor":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "ironhide a secure multicore that efficiently mitigates microarchitecture state attacks for interactive applications")

Question: Please tell me which class the source paper 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)