The liar at address 0x01 There is a function baked into the EVM protocol at 0x01 that has been deceiving developers since the Frontier release in 2015. Not a smart contract bug. Not a compiler issue. …
The sibling Every ECDSA signature (r, s, v) possesses an identical twin (r, n - s, v XOR 1). Same private key signed both. Same message was hashed. ecrecover returns the identical address for both. …
The variable that never moves msg.value does not change inside a loop. That sentence has cost the crypto industry more than a hundred million dollars and it will cost more because the sentence is …
The quiz contract A { function foo() virtual pure returns (string) { return "A"; } } contract B is A { function foo() virtual override pure returns (string) { return "B"; } } contract …
The liar embedded in the protocol extcodesize has been lying to Solidity developers since the Ethereum genesis block. Every developer discovers this lie during an active exploit. Never during …
The beetle that will outlive you The DAO was drained for sixty million dollars on June 17, 2016. I have reviewed twelve contracts in the last six months. Every single one contained the exact same …
Three opcodes and two want you dead The EVM provides three ways to invoke another contract. call sends ETH and returns data. Civilized. Predictable. What a normal engineer would design. staticcall is …