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: "enhancing bitcoin security and performance with strong consistency via collective signing"
  Abstract: While showing great promise, Bitcoin requires users to wait tens of minutes for transactions to commit, and even then, offering only probabilistic guarantees. This paper introduces ByzCoin, a novel Byzantine consensus protocol that leverages scalable collective signing to commit Bitcoin transactions irreversibly within seconds. ByzCoin achieves Byzantine consensus while preserving Bitcoin's open membership by dynamically forming hash power-proportionate consensus groups that represent recently-successful block miners. ByzCoin employs communication trees to optimize transaction commitment and verification under normal operation while guaranteeing safety and liveness under Byzantine faults, up to a near-optimal tolerance of f faulty group members among 3f + 2 total. ByzCoin mitigates double spending and selfish mining attacks by producing collectively signed transaction blocks within one minute of transaction submission. Tree-structured communication further reduces this latency to less than 30 seconds. Due to these optimizations, ByzCoin achieves a throughput higher than PayPal currently handles, with a confirmation latency of 15-20 seconds.

Connected through hyperedge HE-1 (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-2 (induced by source paper "on the feasibility of sybil attacks in shard based permissionless blockchains"):
  with members:
    - "polyshard coded sharding achieves linearly scaling efficiency and security simultaneously"
    - "chain of trust can trusted hardware help scaling blockchains"
    - "towards scaling blockchain systems via sharding"
    - "a survey on security and privacy issues of bitcoin"
    - "lagrange coded computing optimal design for resiliency security and privacy"
    - "blockchain mining games"
    - "solida a blockchain protocol based on reconfigurable byzantine consensus"
    - "centrally banked cryptocurrencies"

Connected through hyperedge HE-3 (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"
    - "solida a blockchain protocol based on reconfigurable byzantine consensus"
    - "optimal selfish mining strategies in bitcoin"
    - "bitcoin ng a scalable blockchain protocol"
    - "majority is not enough bitcoin mining is vulnerable"

Connected through hyperedge HE-4 (induced by source paper "que sera consensus simple asynchronous agreement with private coins and threshold logical clocks"):
  with members:
    - "revisiting fast practical byzantine fault tolerance"
    - "formal verification of multi paxos for distributed consensus"
    - "keeping authorities honest or bust with decentralized witness cosigning"
    - "on reducing the complexity of matrix clocks"
    - "randomized protocols for asynchronous consensus"

Connected through hyperedge HE-5 (induced by source paper "fides managing data on untrusted infrastructure"):
  with members:
    - "parblockchain leveraging transaction parallelism in permissioned blockchain systems"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "chainspace a sharded smart contracts platform"
    - "keeping authorities honest or bust with decentralized witness cosigning"

Connected through hyperedge HE-6 (induced by source paper "resilientdb global scale resilient blockchain fabric"):
  with members:
    - "proof of execution reaching consensus through fault tolerant speculation"
    - "towards scaling blockchain systems via sharding"
    - "blockbench a framework for analyzing private blockchains"
    - "bitcoin ng a scalable blockchain protocol"

Connected through hyperedge HE-7 (induced by source paper "brick asynchronous payment channels"):
  with members:
    - "towards secure and efficient payment channels"
    - "bitcoin meets strong consistency"

Connected through hyperedge HE-8 (induced by source paper "cycledger a scalable and secure parallel protocol for distributed ledger via sharding"):
  with members:
    - "repchain a reputation based secure fast and high incentive blockchain system via sharding"
    - "centrally banked cryptocurrencies"

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)