Security is the cornerstone of the blockchain economy. In the last issue of the Radar, we highlighted the importance of testing and auditing smart contracts dependencies. OpenZeppelin is a framework to help build secure smart contracts in Solidity. The team behind OpenZeppelin summed up a series of pitfalls and best practices around smart contracts' security and embedded these experiences into the source code. The framework is well reviewed and validated by the open source community. We recommend the use of OpenZeppelin instead of writing your own implementation of the ERC20/ERC721 token. OpenZeppelin is also integrated with Truffle.