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: "vandal a scalable security analysis framework for smart contracts"
  Abstract: The rise of modern blockchains has facilitated the emergence of smart contracts: autonomous programs that live and run on the blockchain. Smart contracts have seen a rapid climb to prominence, with applications predicted in law, business, commerce, and governance. #R##N#Smart contracts are commonly written in a high-level language such as Ethereum's Solidity, and translated to compact low-level bytecode for deployment on the blockchain. Once deployed, the bytecode is autonomously executed, usually by a %Turing-complete virtual machine. As with all programs, smart contracts can be highly vulnerable to malicious attacks due to deficient programming methodologies, languages, and toolchains, including buggy compilers. At the same time, smart contracts are also high-value targets, often commanding large amounts of cryptocurrency. Hence, developers and auditors need security frameworks capable of analysing low-level bytecode to detect potential security vulnerabilities. #R##N#In this paper, we present Vandal: a security analysis framework for Ethereum smart contracts. Vandal consists of an analysis pipeline that converts low-level Ethereum Virtual Machine (EVM) bytecode to semantic logic relations. Users of the framework can express security analyses in a declarative fashion: a security analysis is expressed in a logic specification written in the \souffle language. We conduct a large-scale empirical study for a set of common smart contract security vulnerabilities, and show the effectiveness and efficiency of Vandal. Vandal is both fast and robust, successfully analysing over 95\% of all 141k unique contracts with an average runtime of 4.15 seconds; outperforming the current state of the art tools---Oyente, EthIR, Mythril, and Rattle---under equivalent conditions.

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 "smart contract development from the perspective of developers topics and issues discussed on social media"):
  with members:
    - "a survey on ethereum systems security vulnerabilities attacks and defenses"
    - "when energy trading meets blockchain in electrical power system the state of the art"
    - "slither a static analysis framework for smart contracts"
    - "what are the actual flaws in important smart contracts and how can we find them"
    - "verisolid correct by design smart contracts for ethereum"
    - "manticore a user friendly symbolic execution framework for binaries and smart contracts"
    - "tool demonstration fsolidm for designing secure ethereum smart contracts"
    - "finding the greedy prodigal and suicidal contracts at scale"

Connected through hyperedge HE-3 (induced by source paper "vyper a security comparison with solidity based on common vulnerabilities"):
  with members:
    - "a survey on ethereum systems security vulnerabilities attacks and defenses"
    - "verisolid correct by design smart contracts for ethereum"
    - "finding the greedy prodigal and suicidal contracts at scale"
    - "empirical vulnerability analysis of automated smart contracts security testing on blockchains"
    - "towards safer smart contracts a survey of languages and verification methods"
    - "securify practical security analysis of smart contracts"
    - "designing secure ethereum smart contracts a finite state machine based approach"

Connected through hyperedge HE-4 (induced by source paper "smacs smart contract access control service"):
  with members:
    - "online detection of effectively callback free objects with applications to smart contracts"
    - "sereum protecting existing smart contracts against re entrancy attacks"
    - "securify practical security analysis of smart contracts"

Connected through hyperedge HE-5 (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-6 (induced by source paper "a survey on ethereum systems security vulnerabilities attacks and defenses"):
  with members:
    - "security and privacy on blockchain"
    - "exploring the attack surface of blockchain a systematic overview"
    - "a survey on consensus mechanisms and mining strategy management in blockchain networks"
    - "metrics towards measuring cyber agility"
    - "selfish mining in ethereum"
    - "a survey of distributed consensus protocols for blockchain networks"
    - "finding the greedy prodigal and suicidal contracts at scale"
    - "ethir a framework for high level analysis of ethereum bytecode"

Connected through hyperedge HE-7 (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-8 (induced by source paper "smart contract development in practice trends issues and discussions on stack overflow"):
  with members:
    - "a survey on ethereum systems security vulnerabilities attacks and defenses"
    - "when energy trading meets blockchain in electrical power system the state of the art"
    - "slither a static analysis framework for smart contracts"
    - "transax a blockchain based decentralized forward trading energy exchange for transactive microgrids"
    - "what are the actual flaws in important smart contracts and how can we find them"
    - "verisolid correct by design smart contracts for ethereum"
    - "manticore a user friendly symbolic execution framework for binaries and smart contracts"
    - "tool demonstration fsolidm for designing secure ethereum 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.PL(Programming Languages)