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: "sprites and state channels payment networks that go faster than lightning"
  Abstract: Bitcoin, Ethereum and other blockchain-based cryptocurrencies, as deployed today, cannot scale for wide-spread use. A leading approach for cryptocurrency scaling is a smart contract mechanism called a payment channel which enables two mutually distrustful parties to transact efficiently (and only requires a single transaction in the blockchain to set-up). Payment channels can be linked together to form a payment network, such that payments between any two parties can (usually) be routed through the network along a path that connects them. Crucially, both parties can transact without trusting hops along the route. #R##N#In this paper, we propose a novel variant of payment channels, called Sprites, that reduces the worst-case "collateral cost" that each hop along the route may incur. The benefits of Sprites are two-fold. 1) In Lightning Network, a payment across a path of $\ell$ channels requires locking up collateral for $\Theta(\ell\Delta)$ time, where $\Delta$ is the time to commit an on-chain transaction. Sprites reduces this cost to $O(\ell + \Delta)$. 2) Unlike prior work, Sprites supports partial withdrawals and deposits, during which the channel can continue to operate without interruption. #R##N#In evaluating Sprites we make several additional contributions. First, our simulation-based security model is the first formalism to model timing guarantees in payment channels. Our construction is also modular, making use of a generic abstraction from folklore, called the "state channel," which we are the first to formalize. We also provide a simulation framework for payment network protocols, which we use to confirm that the Sprites construction mitigates against throughput-reducing attacks.

Connected through hyperedge HE-1 (induced by source paper "congestion attacks in payment channel networks"):
  with members:
    - "concurrency and privacy with payment channel networks"
    - "privacy utility tradeoffs in routing cryptocurrency over payment channel networks"
    - "hijacking routes in payment channel networks a predictability tradeoff"
    - "topological analysis of bitcoin s lightning network"
    - "discharged payment channels quantifying the lightning network s resilience to topology based attacks"
    - "towards secure and efficient payment channels"

Connected through hyperedge HE-2 (induced by source paper "snappy fast on chain payments with practical collaterals"):
  with members:
    - "dfinity technology overview series consensus system"
    - "gosig scalable byzantine consensus on adversarial wide area network for blockchains"
    - "towards an economic analysis of routing in payment channel networks"
    - "consensus in the age of blockchains"
    - "casper the friendly finality gadget"
    - "strong federations an interoperable blockchain solution to centralized third party risks"

Connected through hyperedge HE-3 (induced by source paper "verifiable and auditable digital interchange framework"):
  with members:
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "chainspace a sharded smart contracts platform"
    - "performance characterization of a commercial video streaming service"
    - "bitcoin ng a scalable blockchain protocol"
    - "centrally banked cryptocurrencies"

Connected through hyperedge HE-4 (induced by source paper "sharper sharding permissioned blockchains over network clusters"):
  with members:
    - "resilientdb global scale resilient blockchain fabric"
    - "parblockchain leveraging transaction parallelism in permissioned blockchain systems"
    - "fastfabric scaling hyperledger fabric to 20 000 transactions per second"
    - "topological analysis of bitcoin s lightning network"
    - "scaling blockchain databases through parallel resilient consensus paradigm"
    - "seemore a fault tolerant protocol for hybrid cloud environments"
    - "streamchain do blockchains need blocks"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"

Connected through hyperedge HE-5 (induced by source paper "towards global asset management in blockchain systems"):
  with members:
    - "atomic commitment across blockchains"
    - "parblockchain leveraging transaction parallelism in permissioned blockchain systems"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "atomic cross chain swaps"
    - "sidechains decoupled consensus between chains"
    - "blockchains consensus protocols in the wild"
    - "adding concurrency to smart contracts"
    - "strong federations an interoperable blockchain solution to centralized third party risks"

Connected through hyperedge HE-6 (induced by source paper "a cryptoeconomic traffic analysis of bitcoins lightning network"):
  with members:
    - "privacy utility tradeoffs in routing cryptocurrency over payment channel networks"
    - "topological analysis of bitcoin s lightning network"
    - "the evolution of lightning network s topology during its first year and the influence over its core values"
    - "payment networks as creation games"
    - "discharged payment channels quantifying the lightning network s resilience to topology based attacks"
    - "ant routing algorithm for the lightning network"
    - "payment network design with fees"
    - "towards an economic analysis of routing in payment channel networks"

Connected through hyperedge HE-7 (induced by source paper "a secure consensus protocol for sidechains"):
  with members:
    - "selfish mining in ethereum"
    - "flash efficient dynamic routing for offchain networks"
    - "proteus a scalable bft consesus protocol for blockchains"
    - "sbft a scalable and decentralized trust infrastructure"
    - "hotstuff bft consensus in the lens of blockchain"
    - "routing cryptocurrency with the spider network"
    - "a scale out blockchain for value transfer with spontaneous sharding"
    - "window based bft blockchain consensus"

Connected through hyperedge HE-8 (induced by source paper "a blueprint for interoperable blockchains"):
  with members:
    - "cross chain deals and adversarial commerce"
    - "towards scaling blockchain systems via sharding"
    - "atomic cross chain swaps"
    - "pdfs practical data feed service for smart contracts"
    - "forkbase an efficient storage engine for blockchain and forkable applications"
    - "securify practical security analysis of smart contracts"
    - "adding concurrency to smart contracts"
    - "blockbench a framework for analyzing private blockchains"

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)