Parity multisig wallets. How did they break?

An overview of the recent wallet incident

Libraries on Ethereum First off, there’s 3 ways to call a function on a contract. CALL, CALLCODE, and DELEGATECALL. Libraries on Ethereum are largely implemented with DELEGATECALL. Meaning, you deploy a contract that serves as a library — it’s got some functions that anyone can call, and can even change the storage of the calling contract. Solidity has some syntactic sugar that lets you declare a library, which does all the DELEGATECALLs for you if you use the library in your contract. [Read More]