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: "atomic cross chain swaps"
  Abstract: An atomic cross-chain swap is a distributed coordination task where multiple parties exchange assets across multiple blockchains, for example, trading bitcoin for ether. #R##N#An atomic swap protocol guarantees (1) if all parties conform to the protocol, then all swaps take place, (2) if some coalition deviates from the protocol, then no conforming party ends up worse off, and (3) no coalition has an incentive to deviate from the protocol. #R##N#A cross-chain swap has an associated directed graph ${\cal D} = (V,A)$. For any pair $({\cal D},L)$, where ${\cal D} = (V,A)$ is a strongly-connected directed graph and $L \subset V$ a feedback vertex set for ${\cal D}$, we give an atomic cross-chain swap protocol using hashed timelock contracts, where the vertexes in $L$ generate the hashlocked secrets. We show that no such protocol is possible if ${\cal D}$ is not strongly connected, or if ${\cal D}$ is strongly connected but $L$ is not a feedback vertex set. The protocol has time complexity $O(diam({\cal D}))$ and communication complexity (bits published on blockchains) $O(|A| \cdot |L|)$.

Connected through hyperedge HE-1 (induced by source paper "throughput optimal routing in blockchain based payment systems"):
  with members:
    - "high throughput cryptocurrency routing in payment channel networks"
    - "settling payments fast and private efficient decentralized routing for path based transactions"
    - "pricing and optimization in shared vehicle systems an approximation framework"
    - "privacy preserving shortest path computation"
    - "online advertisement optimization and stochastic networks"

Connected through hyperedge HE-2 (induced by source paper "distributed cross blockchain transactions"):
  with members:
    - "distributed nonblocking commit protocols for many party cross blockchain transactions"
    - "atomic commitment across blockchains"
    - "cross chain deals and adversarial commerce"
    - "towards scaling blockchain systems via sharding"

Connected through hyperedge HE-3 (induced by source paper "distributed nonblocking commit protocols for many party cross blockchain transactions"):
  with members:
    - "atomic commitment across blockchains"
    - "cross chain deals and adversarial commerce"
    - "towards scaling blockchain systems via sharding"

Connected through hyperedge HE-4 (induced by source paper "appending atomically in byzantine distributed ledgers"):
  with members:
    - "atomic appends selling cars and coordinating armies with multiple distributed ledgers"
    - "blockchain abstract data type"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"

Connected through hyperedge HE-5 (induced by source paper "testimonium a cost efficient blockchain relay"):
  with members:
    - "cross chain deals and adversarial commerce"
    - "blockchain based data provenance for the internet of things"
    - "decentralized applications the blockchain empowered software system"

Connected through hyperedge HE-6 (induced by source paper "the security reference architecture for blockchains towards a standardized model for studying vulnerabilities threats and defenses"):
  with members:
    - "ekiden a platform for confidentiality preserving trustworthy and performant smart contracts"
    - "a survey on ethereum systems security vulnerabilities attacks and defenses"
    - "security and privacy on blockchain"
    - "deconstructing blockchains a comprehensive survey on consensus membership and structure"
    - "truffle tests for free replaying ethereum smart contracts for transparency"
    - "blockchain technologies for the internet of things research issues and challenges"
    - "exploring the attack surface of blockchain a systematic overview"
    - "strongchain transparent and collaborative proof of work consensus"

Connected through hyperedge HE-7 (induced by source paper "blockchains and distributed databases a twin study"):
  with members:
    - "atomic commitment across blockchains"
    - "cross chain deals and adversarial commerce"
    - "blockchain meets database design and implementation of a blockchain relational database"
    - "chain of trust can trusted hardware help scaling blockchains"
    - "blockchain technology overview"
    - "performance evaluation of the quorum blockchain platform"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "towards scaling blockchain systems via sharding"

Connected through hyperedge HE-8 (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"
    - "sidechains decoupled consensus between chains"
    - "blockchains consensus protocols in the wild"
    - "sprites and state channels payment networks that go faster than lightning"
    - "adding concurrency to smart contracts"
    - "strong federations an interoperable blockchain solution to centralized third party risks"

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.DC(Distributed, Parallel, and Cluster Computing)