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: "when money learns to fly towards sensing as a service applications using bitcoin"
  Abstract: Sensing-as-a-Service (S2aaS) is an emerging Internet of Things (IOT) business model pattern. To be technically feasible and to effectively allow for broad adoption, S2aaS implementations have to overcome manifold systemic hurdles, specifically regarding payment and sensor identification. In an effort to overcome these hurdles, we propose Bitcoin as protocol for S2aaS networks. To lay the groundwork and start the conversation about disruptive changes that Bitcoin technology could bring to S2aaS concepts and IOT in general, we identify and discuss the core characteristics that could drive those changes. We present a conceptual example and describe the basic process of exchanging data for cash using Bitcoin.

Connected through hyperedge HE-1 (induced by source paper "implementation of smart contracts using hybrid architectures with on and off blockchain components"):
  with members:
    - "on and off blockchain enforcement of smart contracts"
    - "scilla a smart contract intermediate level language"
    - "towards a design philosophy for interoperable blockchain systems"
    - "designing secure ethereum smart contracts a finite state machine based approach"
    - "runtime verification for business processes utilizing the bitcoin blockchain"
    - "optimized execution of business processes on blockchain"
    - "enigma decentralized computation platform with guaranteed privacy"

Connected through hyperedge HE-2 (induced by source paper "lrcoin leakage resilient cryptocurrency based on bitcoin for data trading in iot"):
  with members:
    - "distributed data vending on blockchain"
    - "incentivized delivery network of iot software updates based on trustless proof of distribution"
    - "securing the internet of things new perspectives and research challenges"
    - "enigma decentralized computation platform with guaranteed privacy"

Connected through hyperedge HE-3 (induced by source paper "the blockchain a new framework for robotic swarm systems"):
  with members:
    - "task allocation in robotic swarms explicit communication based approaches"
    - "sensing as a service model for smart cities supported by internet of things"

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.CY(Computers and Society)