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: "vchain enabling verifiable boolean range queries over blockchain databases"
  Abstract: Blockchains have recently been under the spotlight due to the boom of cryptocurrencies and decentralized applications. There is an increasing demand for querying the data stored in a blockchain database. To ensure query integrity, the user can maintain the entire blockchain database and query the data locally. However, this approach is not economic, if not infeasible, because of the blockchain's huge data size and considerable maintenance costs. In this paper, we take the first step toward investigating the problem of verifiable query processing over blockchain databases. We propose a novel framework, called vChain, that alleviates the storage and computing costs of the user and employs verifiable queries to guarantee the results' integrity. To support verifiable Boolean range queries, we propose an accumulator-based authenticated data structure that enables dynamic aggregation over arbitrary query attributes. Two new indexes are further developed to aggregate intra-block and inter-block data records for efficient query verification. We also propose an inverted prefix tree structure to accelerate the processing of a large number of subscription queries simultaneously. Security analysis and empirical study validate the robustness and practicality of the proposed techniques.

Connected through hyperedge HE-1 (induced by source paper "trends in development of databases and blockchain"):
  with members:
    - "chainifydb how to blockchainify any data management system"
    - "blockchain meets database design and implementation of a blockchain relational database"
    - "sok of used cryptography in blockchain"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "ipfs content addressed versioned p2p file system"

Connected through hyperedge HE-2 (induced by source paper "coinmagic a differential privacy framework for ring signature schemes"):
  with members:
    - "geo indistinguishability differential privacy for location based systems"

Connected through hyperedge HE-3 (induced by source paper "proof of execution reaching consensus through fault tolerant speculation"):
  with members:
    - "blockchain meets database design and implementation of a blockchain relational database"
    - "towards scaling blockchain systems via sharding"
    - "scaling nakamoto consensus to thousands of transactions per second"
    - "the gap game"
    - "proof of work without all the work"
    - "blockbench a framework for analyzing private blockchains"
    - "revisiting fast practical byzantine fault tolerance"
    - "enhancing bitcoin security and performance with strong consistency via collective signing"

Connected through hyperedge HE-4 (induced by source paper "scaling blockchain databases through parallel resilient consensus paradigm"):
  with members:
    - "blockchain meets database design and implementation of a blockchain relational database"
    - "mir bft high throughput bft for blockchains"
    - "towards scaling blockchain systems via sharding"
    - "scaling nakamoto consensus to thousands of transactions per second"
    - "blockbench a framework for analyzing private blockchains"
    - "revisiting fast practical byzantine fault tolerance"

Connected through hyperedge HE-5 (induced by source paper "fspvdsse a forward secure publicly verifiable dynamic sse scheme"):
  with members:
    - "the secure link prediction problem"

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.DB(Databases)