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: "a scalable verification solution for blockchains"
  Abstract: Bitcoin and Ethereum, whose miners arguably collectively comprise the most powerful computational resource in the history of mankind, offer no more power for processing and verifying transactions than a typical smart phone. The system described herein bypasses this bottleneck and brings scalable computation to Ethereum. Our new system consists of a financial incentive layer atop a dispute resolution layer where the latter takes form of a versatile "verification game." In addition to secure outsourced computation, immediate applications include decentralized mining pools whose operator is an Ethereum smart contract, a cryptocurrency with scalable transaction throughput, and a trustless means for transferring currency between disjoint cryptocurrency systems.

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 "blockchain based decentralized applications technology review and development guidelines"):
  with members:
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "casper the friendly finality gadget"
    - "augur a decentralized open source platform for prediction markets"

Connected through hyperedge HE-3 (induced by source paper "towards the uses of blockchain in mobile health services and applications a survey"):
  with members:
    - "controlling robots using artificial intelligence and a consortium blockchain"
    - "an overview of blockchain integration with robotics and artificial intelligence"
    - "a microservice enabled architecture for smart surveillance using blockchain technology"
    - "a survey on the security of blockchain systems"
    - "blockchain and artificial intelligence"
    - "blockchain for cities a systematic literature review"
    - "decentralized applications the blockchain empowered software system"
    - "secure outsourced calculations with homomorphic encryption"

Connected through hyperedge HE-4 (induced by source paper "privacy preserving blockchain mining sybil resistance by proof of useful work"):
  with members:
    - "secure computation for machine learning with spdz"
    - "dfinity technology overview series consensus system"
    - "trustless machine learning contracts evaluating and exchanging machine learning models on the ethereum blockchain"
    - "consensus in the age of blockchains"
    - "enhancing bitcoin security and performance with strong consistency via collective signing"
    - "bitcoin ng a scalable blockchain protocol"
    - "enigma decentralized computation platform with guaranteed privacy"
    - "bitcoin meets strong consistency"

Connected through hyperedge HE-5 (induced by source paper "securely trading unverifiable information without trust"):
  with members:
    - "water from two rocks maximizing the mutual information"
    - "astraea a decentralized blockchain oracle"
    - "betrayal distrust and rationality smart counter collusion contracts for verifiable cloud computing"
    - "smart contract templates essential requirements and design options"
    - "informed truthfulness in multi task peer prediction"
    - "crowdsourced judgement elicitation with endogenous proficiency"
    - "a new approach to practical active secure two party computation"

Connected through hyperedge HE-6 (induced by source paper "ekiden a platform for confidentiality preserving trustworthy and performant smart contracts"):
  with members:
    - "private data objects an overview"
    - "instantaneous decentralized poker"
    - "software grand exposure sgx cache attacks are practical"
    - "malware guard extension using sgx to conceal cache attacks"
    - "stealing machine learning models via prediction apis"
    - "membership inference attacks against machine learning models"

Connected through hyperedge HE-7 (induced by source paper "rational threshold cryptosystems"):
  with members:
    - "dfinity technology overview series consensus system"
    - "casper the friendly finality gadget"
    - "asicboost a speedup for bitcoin mining"
    - "optimal selfish mining strategies in bitcoin"
    - "majority is not enough bitcoin mining is vulnerable"
    - "rational secret sharing and multiparty computation extended abstract"

Connected through hyperedge HE-8 (induced by source paper "building scalable decentralized payment systems"):
  with members:
    - "incentives in ethereum s hybrid casper protocol"
    - "atomic cross chain swaps"
    - "consensus in the age of blockchains"
    - "casper the friendly finality gadget"
    - "invertible bloom lookup tables"

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)