_Follow along with the video_ --- In this section, we covered a comprehensive range of topics including _airdrops_, _signatures_, and _scripting_. We began by exploring more efficient methods for data verification using **Merkle Trees**. These structures allow us to prove that specific data is part of a larger dataset without manually iterating over arrays. Next, we delved into the use and mechanics of **signatures**, which are crucial for ensuring transaction authenticity and integrity. We learned how to generate signatures with `vm.sign` and `cast wallet sign`, and how to implement them within our smart contracts using OpenZeppelin's `ECDSA` library. Following this, we developed few scripts for deploying and interacting with our smart contracts on different platforms, including Anvil, ZKsync local node, and ZKsync Sepolia. Lastly, we examined various transaction types and the principles of the elliptic curve digital signature algorithm (ECDSA). Well done! 🪩 🕺🏼