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: "majority is not enough bitcoin mining is vulnerable"
  Abstract: The Bitcoin cryptocurrency records its transactions in a public log called the blockchain. Its security rests critically on the distributed protocol that maintains the blockchain, run by participants called miners. Conventional wisdom asserts that the protocol is incentive-compatible and secure against colluding minority groups, i.e., it incentivizes miners to follow the protocol as prescribed. #R##N#We show that the Bitcoin protocol is not incentive-compatible. We present an attack with which colluding miners obtain a revenue larger than their fair share. This attack can have significant consequences for Bitcoin: Rational miners will prefer to join the selfish miners, and the colluding group will increase in size until it becomes a majority. At this point, the Bitcoin system ceases to be a decentralized currency. #R##N#Selfish mining is feasible for any group size of colluding miners. We propose a practical modification to the Bitcoin protocol that protects against selfish mining pools that command less than 1/4 of the resources. This threshold is lower than the wrongly assumed 1/2 bound, but better than the current reality where a group of any size can compromise the system.

Connected through hyperedge HE-1 (induced by source paper "on the convergence of artificial intelligence and distributed ledger technology a scoping review and future research agenda"):
  with members:
    - "ekiden a platform for confidentiality preserving trustworthy and performant smart contracts"
    - "energy recycling blockchain with proof of deep learning"
    - "decentralized and collaborative ai on blockchain"
    - "sok transparent dishonesty front running attacks on blockchain"
    - "reliable federated learning for mobile networks"
    - "keystone an open framework for architecting tees"
    - "tensorscone a secure tensorflow framework using intel sgx"
    - "coin ai a proof of useful work scheme for blockchain based distributed deep learning"

Connected through hyperedge HE-2 (induced by source paper "surface a practical blockchain consensus algorithm for real world networks"):
  with members:
    - "rationality is self defeating in permissionless systems"
    - "dfinity technology overview series consensus system"
    - "hotstuff bft consensus in the lens of blockchain"
    - "deconstructing the blockchain to approach physical limits"
    - "scaling nakamoto consensus to thousands of transactions per second"
    - "transaction propagation on permissionless blockchains incentive and routing mechanisms"
    - "implicit consensus blockchain with unbounded throughput"
    - "chainspace a sharded smart contracts platform"

Connected through hyperedge HE-3 (induced by source paper "stability and scalability of blockchain systems"):
  with members:
    - "prism scaling bitcoin by 10 000x"
    - "markov processes in blockchain systems"
    - "decentralization in bitcoin and ethereum networks"
    - "dandelion lightweight cryptocurrency networking with formal anonymity guarantees"
    - "dandelion redesigning the bitcoin network for anonymity"
    - "can p2p networks be super scalable"
    - "stability of a peer to peer communication system"
    - "gossiping with multiple messages"

Connected through hyperedge HE-4 (induced by source paper "fedcoin a peer to peer payment system for federated learning"):
  with members:
    - "explaining deep neural networks with a polynomial time algorithm for shapley values approximation"
    - "advances and open problems in federated learning"
    - "towards efficient data valuation based on the shapley value"
    - "federated learning for edge networks resource optimization and incentive mechanism"
    - "baffle blockchain based aggregator free federated learning"
    - "federated machine learning concept and applications"
    - "blockchained on device federated learning"
    - "communication efficient learning of deep networks from decentralized data"

Connected through hyperedge HE-5 (induced by source paper "incentive analysis of bitcoin ng revisited"):
  with members:
    - "analysis of nakamoto consensus revisited"
    - "scaling nakamoto consensus to thousands of transactions per second"
    - "ohie blockchain scaling made simple"
    - "the gap game"
    - "enhancing bitcoin security and performance with strong consistency via collective signing"
    - "solida a blockchain protocol based on reconfigurable byzantine consensus"
    - "optimal selfish mining strategies in bitcoin"
    - "bitcoin ng a scalable blockchain protocol"

Connected through hyperedge HE-6 (induced by source paper "anchoring the value of cryptocurrency"):
  with members:
    - "decentralization in bitcoin and ethereum networks"
    - "towards scaling blockchain systems via sharding"
    - "dissecting ponzi schemes on ethereum identification analysis and impact"
    - "blockchain based trust authentication for decentralized sensor networks"
    - "smart contract templates foundations design landscape and research directions"
    - "market oriented cloud computing vision hype and reality for delivering it services as computing utilities"
    - "cloud computing and grid computing 360 degree compared"

Connected through hyperedge HE-7 (induced by source paper "coalition safe equilibria with virtual payoffs"):
  with members:
    - "presto a systematic framework for blockchain consensus protocols"
    - "squirrl automating attack discovery on blockchain incentive mechanisms with deep reinforcement learning"
    - "the gap game"
    - "blockchain mining games"
    - "optimal selfish mining strategies in bitcoin"
    - "on bitcoin and red balloons"
    - "an almost surely terminating polynomial protocol for asynchronous byzantine agreement with optimal resilience"

Connected through hyperedge HE-8 (induced by source paper "comparison of decentralization in dpos and pow blockchains"):
  with members:
    - "impossibility of full decentralization in permissionless blockchains"
    - "incentivized blockchain based social media platforms a case study of steemit"
    - "decentralization in bitcoin and ethereum networks"
    - "popularity and quality in social news aggregators a study of reddit and hacker news"
    - "the miner s dilemma"

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)