Yan Michalevsky on smart contract verification
Status: approved Member: Christian Peel Type: Meetup Estimated size: 66 Info URL: https://www.meetup.com/ethereumSiliconValley/ Rooms: Large Event Room
Details: This is a Silicon Valley Ethereum meetup.
Yan Michalevsky will talk on smart contract verification: "The famous DAO bug in the Ethereum blockchain employed callbacks to steal $150M. Callbacks are essential in many programming environments, but drastically complicate program understanding and reasoning because they allow to mutate object’s local states by external objects in unexpected fashions, thus breaking modularity. We define the notion of Effectively Callback Free (ECF) objects in order to allow callbacks without preventing modular reasoning. We study the decidability of dynamically checking ECF in a given execution trace and statically checking if an object is ECF. We also show that dynamically checking ECF in Ethereum is feasible and can be done online. By running the history of all execution traces in Ethereum, we were able to verify that virtually all existing contract executions, excluding these of the DAO or of contracts with similar known vulnerabilities, are ECF. Finally, we show that ECF, whether it is verified dynamically or statically, enables modular reasoning about objects with encapsulated state."