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: "deanonymisation of clients in bitcoin p2p network"
  Abstract: Bitcoin is a digital currency which relies on a distributed set of miners to mint coins and on a peer-to-peer network to broadcast transactions. The identities of Bitcoin users are hidden behind pseudonyms (public keys) which are recommended to be changed frequently in order to increase transaction unlinkability. #R##N#We present an efficient method to deanonymize Bitcoin users, which allows to link user pseudonyms to the IP addresses where the transactions are generated. Our techniques work for the most common and the most challenging scenario when users are behind NATs or firewalls of their ISPs. They allow to link transactions of a user behind a NAT and to distinguish connections and transactions of different users behind the same NAT. We also show that a natural countermeasure of using Tor or other anonymity services can be cut-off by abusing anti-DoS countermeasures of the bitcoin network. Our attacks require only a few machines and have been experimentally verified. We propose several countermeasures to mitigate these new attacks.

Connected through hyperedge HE-1 (induced by source paper "characterizing eosio blockchain"):
  with members:
    - "evulhunter detecting fake transfer vulnerabilities for eosio s smart contracts at webassembly level"
    - "characterizing code clones in the ethereum smart contract ecosystem"
    - "contractfuzzer fuzzing smart contracts for vulnerability detection"
    - "securify practical security analysis of smart contracts"
    - "bitcoin transaction graph analysis"

Connected through hyperedge HE-2 (induced by source paper "the security reference architecture for blockchains towards a standardized model for studying vulnerabilities threats and defenses"):
  with members:
    - "ekiden a platform for confidentiality preserving trustworthy and performant smart contracts"
    - "a survey on ethereum systems security vulnerabilities attacks and defenses"
    - "security and privacy on blockchain"
    - "deconstructing blockchains a comprehensive survey on consensus membership and structure"
    - "truffle tests for free replaying ethereum smart contracts for transparency"
    - "blockchain technologies for the internet of things research issues and challenges"
    - "exploring the attack surface of blockchain a systematic overview"
    - "strongchain transparent and collaborative proof of work consensus"

Connected through hyperedge HE-3 (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-4 (induced by source paper "a security reference architecture for blockchains"):
  with members:
    - "ekiden a platform for confidentiality preserving trustworthy and performant smart contracts"
    - "strongchain transparent and collaborative proof of work consensus"
    - "insight into insiders and it a survey of insider threat taxonomies analysis modeling and countermeasures"
    - "dfinity technology overview series consensus system"
    - "short paper towards more reliable bitcoin timestamps"
    - "the latest gossip on bft consensus"
    - "finding the greedy prodigal and suicidal contracts at scale"
    - "sabre protecting bitcoin against routing attacks"

Connected through hyperedge HE-5 (induced by source paper "blockchains a systematic multivocal literature review"):
  with members:
    - "blockchain technology overview"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "blockchains consensus protocols in the wild"
    - "adding concurrency to smart contracts"
    - "a blockchain based decentralized system for proper handling of temporary employment contracts"
    - "an empirical analysis of smart contracts platforms applications and design patterns"
    - "rollback and forking detection for trusted execution environments using lightweight collective memory"
    - "blockbench a framework for analyzing private blockchains"

Connected through hyperedge HE-6 (induced by source paper "privacy utility tradeoffs in routing cryptocurrency over payment channel networks"):
  with members:
    - "concurrency and privacy with payment channel networks"
    - "celer network bring internet scale to every blockchain"
    - "routing cryptocurrency with the spider network"
    - "ohie blockchain scaling made simple"
    - "high throughput cryptocurrency routing in payment channel networks"
    - "dandelion redesigning the bitcoin network for anonymity"
    - "settling payments fast and private efficient decentralized routing for path based transactions"
    - "extremal mechanisms for local differential privacy"

Connected through hyperedge HE-7 (induced by source paper "bandwidth efficient transaction relay for bitcoin"):
  with members:
    - "dandelion lightweight cryptocurrency networking with formal anonymity guarantees"
    - "txprobe discovering bitcoin s network topology using orphan transactions"
    - "bitcoin ng a scalable blockchain protocol"
    - "multi party set reconciliation using characteristic polynomials"
    - "bitcoin transaction malleability and mtgox"
    - "majority is not enough bitcoin mining is vulnerable"
    - "simple multi party set reconciliation"
    - "hosting byzantine fault tolerant services on a chord ring"

Connected through hyperedge HE-8 (induced by source paper "bitcoin and blockchain security and privacy"):
  with members:
    - "a survey on security and privacy issues of bitcoin"
    - "an explanation of nakamoto s analysis of double spend attacks"
    - "hijacking bitcoin routing attacks on cryptocurrencies"
    - "analysis of hashrate based double spending"
    - "bitcoin over tor isn t a good idea"
    - "analysis of bitcoin pooled mining reward systems"
    - "de anonymizing social networks"

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)