?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=On+the+Just-In-Time+Discovery+of+Profit-Generating+Transactions+in+DeFi+Protocols&rft.creator=Zhou%2C+Liyi&rft.creator=Qin%2C+Kaihua&rft.creator=Cully%2C+Antoine&rft.creator=Livshits%2C+Benjamin&rft.creator=Gervais%2C+Arthur&rft.description=Decentralized+Finance+(DeFi)+is+a+blockchain-asset-enabled+finance+ecosystem+with+millions+of+daily+USD+transaction+volume%2C+billions+of+locked+up+USD%2C+as+well+as+a+plethora+of+newly+emerging+protocols+(for+lending%2C+staking%2C+and+exchanges).+Because+all+transactions%2C+user+balances%2C+and+total+value+locked+in+DeFi+are+publicly+readable%2C+a+natural+question+that+arises+is%3A+how+can+we+automatically+craft+profitable+transactions+across+the+intertwined+DeFi+platforms%3FIn+this+paper%2C+we+investigate+two+methods+that+allow+us+to+automatically+create+profitable+DeFi+trades%2C+one+well-suited+to+arbitrage+and+the+other+applicable+to+more+complicated+settings.+We+first+adopt+the+Bellman-Ford-Moore+algorithm+with+DeFiPoser-ARB+and+then+create+logical+DeFi+protocol+models+for+a+theorem+prover+in+DeFiPoser-SMT.+While+DeFiPoser-ARB+focuses+on+DeFi+transactions+that+form+a+cycle+and+performs+very+well+for+arbitrage%2C+DeFiPoser-SMT+can+detect+more+complicated+profitable+transactions.+We+estimate+that+DeFiPoser-ARB+and+DeFiPoser-SMT+can+generate+an+average+weekly+revenue+of+191.48+ETH+(76%2C592+USD)+and+72.44+ETH+(28%2C976+USD)+respectively%2C+with+the+highest+transaction+revenue+being+81.31+ETH+(32%2C524+USD)+and+22.40+ETH+(8%2C960+USD)+respectively.+We+further+show+that+DeFiPoser-SMT+finds+the+known+economic+bZx+attack+from+February+2020%2C+which+yields+0.48M+USD.+Our+forensic+investigations+show+that+this+opportunity+existed+for+69+days+and+could+have+yielded+more+revenue+if+exploited+one+day+earlier.+Our+evaluation+spans+150+days%2C+given+96+DeFi+protocol+actions%2C+and+25+assets.Looking+beyond+the+financial+gains+mentioned+above%2C+forks+deteriorate+the+blockchain+consensus+security%2C+as+they+increase+the+risks+of+double-spending+and+selfish+mining.+We+explore+the+implications+of+DeFiPoser-ARB+and+DeFiPoser-SMT+on+blockchain+consensus.+Specifically%2C+we+show+that+the+trades+identified+by+our+tools+exceed+the+Ethereum+block+reward+by+up+to+874%C3%97.+Given+optimal+adversarial+strategies+provided+by+a+Markov+Decision+Process+(MDP)%2C+we+quantify+the+value+threshold+at+which+a+profitable+transaction+qualifies+as+Miner+Extractable+Value+(MEV)+and+would+incentivize+MEV-aware+miners+to+fork+the+blockchain.+For+instance%2C+we+find+that+on+Ethereum%2C+a+miner+with+a+hash+rate+of+10%25+would+fork+the+blockchain+if+an+MEV+opportunity+exceeds+4%C3%97+the+block+reward.&rft.publisher=IEEE&rft.date=2021-08-26&rft.type=Proceedings+paper&rft.language=eng&rft.source=+++++In%3A++2021+IEEE+Symposium+on+Security+and+Privacy+(SP).++(pp.+pp.+919-936).++IEEE%3A+San+Francisco%2C+CA%2C+USA.+(2021)+++++&rft.format=text&rft.identifier=https%3A%2F%2Fdiscovery.ucl.ac.uk%2Fid%2Feprint%2F10182331%2F1%2F2103.02228.pdf&rft.identifier=https%3A%2F%2Fdiscovery.ucl.ac.uk%2Fid%2Feprint%2F10182331%2F&rft.rights=open