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: "adding concurrency to smart contracts"
  Abstract: Modern cryptocurrency systems, such as Ethereum, permit complex financial transactions through scripts called smart contracts. These smart contracts are executed many, many times, always without real concurrency. First, all smart contracts are serially executed by miners before appending them to the blockchain. Later, those contracts are serially re-executed by validators to verify that the smart contracts were executed correctly by miners. #R##N#Serial execution limits system throughput and fails to exploit today's concurrent multicore and cluster architectures. Nevertheless, serial execution appears to be required: contracts share state, and contract programming languages have a serial semantics. #R##N#This paper presents a novel way to permit miners and validators to execute smart contracts in parallel, based on techniques adapted from software transactional memory. Miners execute smart contracts speculatively in parallel, allowing non-conflicting contracts to proceed concurrently, and "discovering" a serializable concurrent schedule for a block's transactions, This schedule is captured and encoded as a deterministic fork-join program used by validators to re-execute the miner's parallel schedule deterministically but concurrently. #R##N#Smart contract benchmarks run on a JVM with ScalaSTM show that a speedup of of 1.33x can be obtained for miners and 1.69x for validators with just three concurrent threads.

Connected through hyperedge HE-1 (induced by source paper "an overview on smart contracts challenges advances and platforms"):
  with members:
    - "the art of the scam demystifying honeypots in ethereum smart contracts"
    - "blockchain for internet of things a survey"
    - "evmfuzz differential fuzz testing of ethereum virtual machine"
    - "tool demonstration fsolidm for designing secure ethereum smart contracts"
    - "finding the greedy prodigal and suicidal contracts at scale"
    - "ethir a framework for high level analysis of ethereum bytecode"
    - "sabre protecting bitcoin against routing attacks"
    - "hunting the ethereum smart contract color inspired inspection of potential attacks"

Connected through hyperedge HE-2 (induced by source paper "on exploiting transaction concurrency to speed up blockchains"):
  with members:
    - "blockchains and distributed databases a twin study"
    - "the security reference architecture for blockchains towards a standardized model for studying vulnerabilities threats and defenses"
    - "an empirical study of speculative concurrency in ethereum smart contracts"
    - "hotstuff bft consensus in the lens of blockchain"
    - "a concurrent perspective on smart contracts"
    - "blockbench a framework for analyzing private blockchains"
    - "untangling blockchain a data processing view of blockchain systems"

Connected through hyperedge HE-3 (induced by source paper "security analysis methods on ethereum smart contract vulnerabilities a survey"):
  with members:
    - "easyflow keep ethereum away from overflow"
    - "a security case study for blockchain games"
    - "a hybrid formal verification system in coq for ensuring the reliability and security of ethereum based service smart contracts"
    - "finding the greedy prodigal and suicidal contracts at scale"
    - "ethir a framework for high level analysis of ethereum bytecode"
    - "formal process virtual machine for smart contracts verification"
    - "scilla a smart contract intermediate level language"
    - "empirical vulnerability analysis of automated smart contracts security testing on blockchains"

Connected through hyperedge HE-4 (induced by source paper "blockchains and distributed databases a twin study"):
  with members:
    - "atomic commitment across blockchains"
    - "cross chain deals and adversarial commerce"
    - "blockchain meets database design and implementation of a blockchain relational database"
    - "chain of trust can trusted hardware help scaling blockchains"
    - "blockchain technology overview"
    - "performance evaluation of the quorum blockchain platform"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "towards scaling blockchain systems via sharding"

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"
    - "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"
    - "untangling blockchain a data processing view of blockchain systems"

Connected through hyperedge HE-6 (induced by source paper "towards global asset management in blockchain systems"):
  with members:
    - "atomic commitment across blockchains"
    - "parblockchain leveraging transaction parallelism in permissioned blockchain systems"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "atomic cross chain swaps"
    - "sidechains decoupled consensus between chains"
    - "blockchains consensus protocols in the wild"
    - "sprites and state channels payment networks that go faster than lightning"
    - "strong federations an interoperable blockchain solution to centralized third party risks"

Connected through hyperedge HE-7 (induced by source paper "ostraka secure blockchain scaling by node sharding"):
  with members:
    - "decentralization in bitcoin and ethereum networks"
    - "hotstuff bft consensus in the lens of blockchain"
    - "split scale scaling bitcoin by partitioning the utxo space"
    - "dietcoin shortcutting the bitcoin verification process for your smartphone"
    - "chainspace a sharded smart contracts platform"
    - "casper the friendly finality gadget"
    - "enhancing bitcoin security and performance with strong consistency via collective signing"
    - "service oriented sharding with aspen"

Connected through hyperedge HE-8 (induced by source paper "a true concurrent model of smart contracts executions"):
  with members:
    - "a minimal core calculus for solidity contracts"
    - "verisolid correct by design smart contracts for ethereum"
    - "scilla a smart contract intermediate level language"
    - "detecting token systems on ethereum"
    - "a semantic framework for the security analysis of ethereum smart contracts"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "an efficient framework for optimistic concurrent execution of smart contracts"
    - "securify practical security analysis of smart contracts"

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)