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: "using block chain for peer to peer proof of location"
  Abstract: Location-Based Services (LBSs) build upon geographic information to provide users with location-dependent functionalities. In such a context, it is particularly important that geographic locations claimed by users are the actual ones. Centralized verification approaches proposed in the last few years are not satisfactory, as they entail a high risk to the privacy of users. In this paper, we present and evaluate a novel decentralized, infrastructure-independent proof-of-location scheme based on the blockchain technology. Our scheme guarantees both location trustworthiness and user privacy preservation.

Connected through hyperedge HE-1 (induced by source paper "deconstructing blockchains a comprehensive survey on consensus membership and structure"):
  with members:
    - "dfinity technology overview series consensus system"
    - "analysis of the xrp ledger consensus protocol"
    - "hotstuff bft consensus in the lens of blockchain"
    - "evaluating the red belly blockchain"
    - "an empirical analysis of anonymity in zcash"
    - "a survey on security and privacy issues of bitcoin"
    - "blockchains consensus protocols in the wild"
    - "cachezoom how sgx amplifies the power of cache attacks"

Connected through hyperedge HE-2 (induced by source paper "dmap a distributed blockchain based framework for online mapping in smart city"):
  with members:
    - "speedychain a framework for decoupling data from blockchain for smart cities"
    - "blockchain a distributed solution to automotive security and privacy"
    - "blockchain based intelligent vehicle data sharing framework"

Connected through hyperedge HE-3 (induced by source paper "a privacy preserving accountable and spam resilient geo marketplace"):
  with members:
    - "blockchain technologies for the internet of things research issues and challenges"
    - "modelchain decentralized privacy preserving healthcare predictive modeling framework on private blockchain networks"

Connected through hyperedge HE-4 (induced by source paper "a decentralized method for making sensor measurements tamper proof to support open science applications"):
  with members:
    - "decentralized trusted timestamping using the crypto currency bitcoin"

Connected through hyperedge HE-5 (induced by source paper "speedychain a framework for decoupling data from blockchain for smart cities"):
  with members:
    - "a survey on security and privacy issues of bitcoin"
    - "blockchain a distributed solution to automotive security and privacy"
    - "secure vehicular communication systems design and architecture"

Connected through hyperedge HE-6 (induced by source paper "lsb a lightweight scalable blockchain for iot security and privacy"):
  with members:
    - "the blockchain a new framework for robotic swarm systems"

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.DC(Distributed, Parallel, and Cluster Computing)