In this tutorial I will explain how to access private data on the Ethereum blockchain. All data on the blockchain…
Reentrancy attack in a Solidity smart contract
A reentrancy attack in a Solidity smart contract is a common exploit. These attacks can completely drain your smart contract…
Covered call smart contract in Solidity
Below is a Solidity covered call smart contract. The seller deposits tokens into the contract and earns a fee selling…
Create a multi sig (signature) wallet in Solidity
Create a multi sig (signature) wallet in Solidity. Most cryptocurrency wallets need one signature (private key) to sign and process…
Delegate call to upgrade a solidity smart contract
Use a delegate call to upgrade a Solidity smart contract. A delegate call function runs code of the call in…
Arithmetic Overflow and underflow
Envision an older car’s odometer (non digital) that only supports 999,999. Once it crosses 999,999 it will revert back to…
Ethereum GETH Node Configuration in Docker
To get started using Ethereum GETH download and Install GETH from Docker or the GETH home page. On their website…
Ethereum Gas Resources
Use the link below to determine the current gas prices on the Ethereum network. One can use Etherscan too as…