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: "a blockchain based approach for data accountability and provenance tracking"
  Abstract: The recent approval of the General Data Protection Regulation (GDPR) imposes new data protection requirements on data controllers and processors with respect to the processing of European Union (EU) residents' data. These requirements consist of a single set of rules that have binding legal status and should be enforced in all EU member states. In light of these requirements, we propose in this paper the use of a blockchain-based approach to support data accountability and provenance tracking. Our approach relies on the use of publicly auditable contracts deployed in a blockchain that increase the transparency with respect to the access and usage of data. We identify and discuss three different models for our approach with different granularity and scalability requirements where contracts can be used to encode data usage policies and provenance tracking information in a privacy-friendly way. From these three models we designed, implemented, and evaluated a model where contracts are deployed by data subjects for each data controller, and a model where subjects join contracts deployed by data controllers in case they accept the data handling conditions. Our implementations show in practice the feasibility and limitations of contracts for the purposes identified in this paper.

Connected through hyperedge HE-1 (induced by source paper "joint time scheduling and transaction fee selection in blockchain based rf powered backscatter cognitive radio network"):
  with members:
    - "deep reinforcement learning for time scheduling in rf powered backscatter cognitive radio networks"
    - "reinforcement learning approach for rf powered cognitive radio network with ambient backscatter"
    - "riding on the primary a new spectrum sharing paradigm for wireless powered iot devices"
    - "wireless powered asynchronous backscatter networks with sporadic short packets performance analysis and optimization"
    - "deep reinforcement learning for dynamic multichannel access in wireless networks"
    - "stackelberg game for distributed time scheduling in rf powered backscatter cognitive radio networks"
    - "blockchained on device federated learning"
    - "joint transaction transmission and channel selection in cognitive radio based blockchain networks a deep reinforcement learning approach"

Connected through hyperedge HE-2 (induced by source paper "from trend analysis to new virtual world system design requirements and requirement satisfaction study"):
  with members:
    - "virtual net a decentralized architecture for interaction in mobile virtual worlds"
    - "procedural content generation via machine learning pcgml"
    - "virtual world defined from a technological perspective and applied to video games mixed reality and the metaverse"
    - "the hot potato case challenges in multiplayer pervasive games based on ad hoc mobile sensor networks and the experimental evaluation of a prototype game"

Connected through hyperedge HE-3 (induced by source paper "mind the gap trade offs between distributed ledger technology characteristics"):
  with members:
    - "on the origins and variations of blockchain technologies"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "a survey on the security of blockchain systems"
    - "blockbench a framework for analyzing private blockchains"
    - "untangling blockchain a data processing view of blockchain systems"
    - "zeroblock preventing selfish mining in bitcoin"
    - "hijacking bitcoin routing attacks on cryptocurrencies"
    - "the blockchain anomaly"

Connected through hyperedge HE-4 (induced by source paper "gdpr compliant personal data management a blockchain based solution"):
  with members:
    - "a survey on consensus mechanisms and mining strategy management in blockchain networks"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "towards blockchain based auditable storage and sharing of iot data"
    - "blockbench a framework for analyzing private blockchains"
    - "untangling blockchain a data processing view of blockchain systems"
    - "xft practical fault tolerance beyond crashes"
    - "ipfs content addressed versioned p2p file system"

Connected through hyperedge HE-5 (induced by source paper "on the ethereum blockchain structure a complex networks theory perspective"):
  with members:
    - "likestarter a smart contract based social dao for crowdfunding"
    - "towards blockchain enabled wireless mesh networks"
    - "a blockchain based flight data recorder for cloud accountability"
    - "towards blockchain based auditable storage and sharing of iot data"
    - "smart contract slas for dense small cell as a service"
    - "highly intensive data dissemination in complex networks"
    - "simulation of the internet of things"

Connected through hyperedge HE-6 (induced by source paper "security services using blockchains a state of the art survey"):
  with members:
    - "a survey on security and privacy issues of bitcoin"
    - "towards blockchain based auditable storage and sharing of iot data"
    - "blockchain based trust authentication for decentralized sensor networks"
    - "using blockchain and smart contracts for secure data provenance management"
    - "blockbench a framework for analyzing private blockchains"
    - "bitcoin ng a scalable blockchain protocol"

Connected through hyperedge HE-7 (induced by source paper "luce a blockchain solution for monitoring data license accountability and compliance"):
  with members:
    - "using blockchain and smart contracts for secure data provenance management"

Connected through hyperedge HE-8 (induced by source paper "joint transaction transmission and channel selection in cognitive radio based blockchain networks a deep reinforcement learning approach"):
  with members:
    - "deep reinforcement learning for dynamic multichannel access in wireless networks"
    - "deep reinforcement learning with double q learning"
    - "analysis of hashrate based double spending"

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)