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: "on profitability of selfish mining"
  Abstract: We review the so called selfish mining strategy in the Bitcoin network and compare its profitability to honest mining.We build a rigorous profitability model for repetition games. The time analysis of the attack has been ignored in the previous literature based on a Markov model,but is critical. Using martingale's techniques and Doob Stopping Time Theorem we compute the expected duration of attack cycles. We discover a remarkable property of the bitcoin network: no strategy is more profitable than the honest strategy before a difficulty adjustment. So selfish mining can only become profitable afterwards, thus it is an attack on the difficulty adjustment algorithm. We propose an improvement of Bitcoin protocol making it immune to selfish mining attacks. We also study miner's attraction to selfish mining pools. We calculate the expected duration time before profit for the selfish miner, a computation that is out of reach by the previous Markov models.

Connected through hyperedge HE-1 (induced by source paper "on profitability of nakamoto double spend"):
  with members:
    - "profitable double spending attacks"
    - "on profitability of stubborn mining"
    - "on profitability of trailing mining"
    - "double spend races"
    - "an analysis of attacks on blockchain consensus"
    - "analysis of hashrate based double spending"

Connected through hyperedge HE-2 (induced by source paper "selfish mining in ethereum"):
  with members:
    - "selfish mining in ethereum"
    - "bitcoin selfish mining and dyck words"
    - "selfish mining and dyck words in bitcoin and ethereum networks"
    - "on profitability of trailing mining"
    - "the impact of uncle rewards on selfish mining in ethereum"
    - "majority is not enough bitcoin mining is vulnerable"

Connected through hyperedge HE-3 (induced by source paper "agent based simulations of blockchain protocols illustrated via kadena s chainweb"):
  with members:
    - "decentralization in bitcoin and ethereum networks"
    - "dfinity technology overview series consensus system"
    - "a stochastic game framework for analyzing computational investment strategies in distributed computing with application to blockchain mining"
    - "a unified game theoretic approach to multiagent reinforcement learning"
    - "end to end learning for self driving cars"

Connected through hyperedge HE-4 (induced by source paper "bitcoin selfish mining and dyck words"):
  with members:
    - "on profitability of stubborn mining"
    - "on profitability of trailing mining"
    - "majority is not enough bitcoin mining is vulnerable"

Connected through hyperedge HE-5 (induced by source paper "selfish mining and dyck words in bitcoin and ethereum networks"):
  with members:
    - "selfish mining in ethereum"
    - "on profitability of stubborn mining"
    - "on profitability of trailing mining"

Connected through hyperedge HE-6 (induced by source paper "on profitability of trailing mining"):
  with members:
    - "on profitability of stubborn mining"
    - "double spend races"
    - "majority is not enough bitcoin mining is vulnerable"

Connected through hyperedge HE-7 (induced by source paper "on profitability of stubborn mining"):
  with members:
    - "double spend races"
    - "majority is not enough bitcoin mining is vulnerable"

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.GT(Computer Science and Game Theory)