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: "decentralized user centric access control using pubsub over blockchain"
  Abstract: We present a mechanism that puts users in the center of control and empowers them to dictate the access to their collections of data. Revisiting the fundamental mechanisms in security for providing protection, our solution uses capabilities, access lists, and access rights following well-understood formal notions for reasoning about access. This contribution presents a practical, correct, auditable, transparent, distributed, and decentralized mechanism that is well-matched to the current emerging environments including Internet of Things, smart city, precision medicine, and autonomous cars. It is based on well-tested principles and practices used in a distributed authorization, cryptocurrencies, and scalable computing.

Connected through hyperedge HE-1 (induced by source paper "sok of used cryptography in blockchain"):
  with members:
    - "sef a secure fountain architecture for slashing storage costs in blockchains"
    - "dfinity technology overview series consensus system"
    - "celer network bring internet scale to every blockchain"
    - "raziel private and verifiable smart contracts on blockchains"
    - "blendcac a blockchain enabled decentralized capability based access control for iots"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "a survey on security and privacy issues of bitcoin"
    - "privacy preserving and efficient aggregation based on blockchain for power grid communications in smart communities"

Connected through hyperedge HE-2 (induced by source paper "consentio managing consent to data access using permissioned blockchains"):
  with members:
    - "parblockchain leveraging transaction parallelism in permissioned blockchain systems"
    - "fastfabric scaling hyperledger fabric to 20 000 transactions per second"
    - "a blockchain based scheme for access control in e health scenarios"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "performance benchmarking and optimizing hyperledger fabric blockchain platform"
    - "smart contract based access control for the internet of things"
    - "secure and trustable electronic medical records sharing using blockchain"

Connected through hyperedge HE-3 (induced by source paper "distributed access control with blockchain"):
  with members:
    - "performance benchmarking and optimizing hyperledger fabric blockchain platform"
    - "towards blockchain enabled wireless mesh networks"
    - "ipchain securing ip prefix allocation and delegation with blockchain"
    - "xft practical fault tolerance beyond crashes"

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)