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: "bitcoin s security model revisited"
  Abstract: We revisit the fundamental question of Bitcoin's security against double spending attacks. While previous work has bounded the probability that a transaction is reversed, we show that no such guarantee can be effectively given if the attacker can choose when to launch the attack. Other approaches that bound the cost of an attack have erred in considering only limited attack scenarios, and in fact it is easy to show that attacks may not cost the attacker at all. We therefore provide a different interpretation of the results presented in previous papers and correct them in several ways. We provide different notions of the security of transactions that provide guarantees to different classes of defenders: merchants who regularly receive payments, miners, and recipients of large one-time payments. We additionally consider an attack that can be launched against lightweight clients, and show that these are less secure than their full node counterparts and provide the right strategy for defenders in this case as well. Our results, overall, improve the understanding of Bitcoin's security guarantees and provide correct bounds for those wishing to safely accept transactions.

Connected through hyperedge HE-1 (induced by source paper "a survey on consensus mechanisms and mining strategy management in blockchain networks"):
  with members:
    - "decentralization in bitcoin and ethereum networks"
    - "information and communications technologies for sustainable development goals state of the art needs and perspectives"
    - "a scale out blockchain for value transfer with spontaneous sharding"
    - "a survey on security and privacy issues of bitcoin"
    - "on cyber risk management of blockchain networks a game theoretic approach"
    - "scaling nakamoto consensus to thousands of transactions per second"
    - "competitive data trading in wireless powered internet of things iot crowdsensing systems with blockchain"
    - "blockchained on device federated learning"

Connected through hyperedge HE-2 (induced by source paper "markov processes in blockchain systems"):
  with members:
    - "a survey on consensus mechanisms and mining strategy management in blockchain networks"
    - "profitable double spending attacks"
    - "performance analysis of the raft consensus algorithm for private blockchains"
    - "a probabilistic model of the bitcoin blockchain"
    - "block arrivals in the bitcoin blockchain"
    - "blockchains consensus protocols in the wild"
    - "blockchain based smart contracts a systematic mapping study"
    - "an empirical analysis of smart contracts platforms applications and design patterns"

Connected through hyperedge HE-3 (induced by source paper "a deep dive into bitcoin mining pools an empirical analysis of mining shares"):
  with members:
    - "decentralization in bitcoin and ethereum networks"
    - "estimation of miner hash rates and consensus on blockchains draft"
    - "the unreasonable effectiveness of address clustering"
    - "optimal selfish mining strategies in bitcoin"
    - "analysis of hashrate based double spending"
    - "on subversive miner strategies and block withholding attack in bitcoin digital currency"
    - "the miner s dilemma"
    - "majority is not enough bitcoin mining is vulnerable"

Connected through hyperedge HE-4 (induced by source paper "ergodic mean payoff games for the analysis of attacks in crypto currencies"):
  with members:
    - "quantitative analysis of smart contracts"
    - "optimal selfish mining strategies in bitcoin"
    - "the complexity of ergodic mean payoff games"
    - "analysis of hashrate based double spending"
    - "the miner s dilemma"
    - "majority is not enough bitcoin mining is vulnerable"
    - "pareto curves for probabilistic model checking"
    - "analysis of bitcoin pooled mining reward systems"

Connected through hyperedge HE-5 (induced by source paper "quantitative analysis of smart contracts"):
  with members:
    - "ergodic mean payoff games for the analysis of attacks in crypto currencies"
    - "optimal selfish mining strategies in bitcoin"
    - "qualitative analysis of concurrent mean payoff games"
    - "counterexample guided planning"
    - "better quality in synthesis through quantitative objectives"

Connected through hyperedge HE-6 (induced by source paper "all roads lead to rome many ways to double spend your cryptocurrency"):
  with members:
    - "a survey on security and privacy issues of bitcoin"

Connected through hyperedge HE-7 (induced by source paper "database perspectives on blockchains"):
  with members:
    - "analysis of bitcoin pooled mining reward systems"

Connected through hyperedge HE-8 (induced by source paper "strong federations an interoperable blockchain solution to centralized third party risks"):
  with members:
    - "enhancing bitcoin security and performance with strong consistency via collective signing"
    - "bitcoin ng a scalable blockchain protocol"
    - "byzantine attack and defense in cognitive radio networks a survey"

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)