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: "an adaptive gas cost mechanism for ethereum to defend against under priced dos attacks"
  Abstract: The gas mechanism in Ethereum charges the execution of every operation to ensure that smart contracts running in EVM (Ethereum Virtual Machine) will be eventually terminated. Failing to properly set the gas costs of EVM operations allows attackers to launch DoS attacks on Ethereum. Although Ethereum recently adjusted the gas costs of EVM operations to defend against known DoS attacks, it remains unknown whether the new setting is proper and how to configure it to defend against unknown DoS attacks. In this paper, we make the first step to address this challenging issue by first proposing an emulation-based framework to automatically measure the resource consumptions of EVM operations. The results reveal that Ethereum's new setting is still not proper. Moreover, we obtain an insight that there may always exist exploitable under-priced operations if the cost is fixed. Hence, we propose a novel gas cost mechanism, which dynamically adjusts the costs of EVM operations according to the number of executions, to thwart DoS attacks. This method punishes the operations that are executed much more frequently than before and lead to high gas costs. To make our solution flexible and secure and avoid frequent update of Ethereum client, we design a special smart contract that collaborates with the updated EVM for dynamic parameter adjustment. Experimental results demonstrate that our method can effectively thwart both known and unknown DoS attacks with flexible parameter settings. Moreover, our method only introduces negligible additional gas consumption for benign users.

Connected through hyperedge HE-1 (induced by source paper "step on the gas a better approach for recommending the ethereum gas price"):
  with members:
    - "fast fourier forecasting resource utilisation in distributed systems"
    - "empirically analyzing ethereum s gas mechanism"
    - "broken metre attacking resource metering in evm"
    - "gastap a gas analyzer for smart contracts"
    - "towards safer smart contracts a survey of languages and verification methods"
    - "under optimized smart contracts devour your money"
    - "adam a method for stochastic optimization"
    - "learning phrase representations using rnn encoder decoder for statistical machine translation"

Connected through hyperedge HE-2 (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-3 (induced by source paper "exploring the attack surface of blockchain a systematic overview"):
  with members:
    - "scalable byzantine consensus via hardware assisted secret sharing"
    - "security services using blockchains a state of the art survey"
    - "a survey on the security of blockchain systems"
    - "an empirical analysis of anonymity in zcash"
    - "towards blockchain driven secure and transparent audit logs"
    - "end to end analysis of in browser cryptojacking"
    - "linbft linear communication byzantine fault tolerance for public blockchains"
    - "a survey on security and privacy issues of bitcoin"

Connected through hyperedge HE-4 (induced by source paper "gasfuzz generating high gas consumption inputs to avoid out of gas vulnerability"):
  with members:
    - "evmfuzz differential fuzz testing of ethereum virtual machine"
    - "the ico phenomenon and its relationships with ethereum smart contract environment"
    - "gastap a gas analyzer for smart contracts"
    - "contractfuzzer fuzzing smart contracts for vulnerability detection"
    - "a semantic framework for the security analysis of ethereum smart contracts"
    - "enfuzz from ensemble learning to ensemble fuzzing"
    - "vandal a scalable security analysis framework for smart contracts"
    - "securify practical security analysis of smart contracts"

Connected through hyperedge HE-5 (induced by source paper "xblock eth extracting and exploring blockchain data from ethereum"):
  with members:
    - "blockchain for internet of things a survey"
    - "measurement and analysis of the bitcoin networks a view from mining pools"
    - "decentralization in bitcoin and ethereum networks"
    - "contractfuzzer fuzzing smart contracts for vulnerability detection"
    - "dissecting ponzi schemes on ethereum identification analysis and impact"
    - "blocksci design and applications of a blockchain analysis platform"
    - "blockbench a framework for analyzing private blockchains"
    - "online human bot interactions detection estimation and characterization"

Connected through hyperedge HE-6 (induced by source paper "broken metre attacking resource metering in evm"):
  with members:
    - "gastap a gas analyzer for smart contracts"
    - "contractfuzzer fuzzing smart contracts for vulnerability detection"
    - "towards safer smart contracts a survey of languages and verification methods"
    - "vandal a scalable security analysis framework for smart contracts"
    - "securify practical security analysis of smart contracts"
    - "chainspace a sharded smart contracts platform"
    - "under optimized smart contracts devour your money"
    - "majority is not enough bitcoin mining is vulnerable"

Connected through hyperedge HE-7 (induced by source paper "a first look at blockchain based decentralized applications"):
  with members:
    - "a blockchain enabled trustless crowd intelligence ecosystem on mobile edge computing"
    - "proofware proof of useful work blockchain consensus protocol for decentralized applications"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "scompile critical path identification and analysis for smart contracts"
    - "blockchain oriented software engineering challenges and new directions"
    - "under optimized smart contracts devour your money"

Connected through hyperedge HE-8 (induced by source paper "the economics of smart contracts"):
  with members:
    - "blockchain meets database design and implementation of a blockchain relational database"
    - "incentives in ethereum s hybrid casper protocol"
    - "empirically analyzing ethereum s gas mechanism"
    - "broken metre attacking resource metering in evm"
    - "casper the friendly finality gadget"

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)