Ethernaut challenges are a series of online puzzles that test a user’s knowledge of the Ethereum blockchain and smart contract programming.

Account abstraction is a concept that refers to the future of wallet signing mechanisms. Currently, the signature mechanism used by mainstream wallets, known as EOAs, is the CDSA (Elliptic Curve Digital Algorithm Signature). However, the signature mechanism of future wallets could be diversified, potentially using multi-sig, other encryption algorithms, and ZK verification. The proposal of EIP-4337 promotes the implementation of the Account abstraction, which may pave the way for a new era of self-custodial wallets. This feature allows users to send and receive transactions, as well as deploy and interact with smart contracts, using their own accounts. The account abstraction also enables users to control their own private keys, giving them full ownership and control over their assets and transactions on the Ethereum network.

Smart contracts are self-executing pieces of code that run on blockchain platforms like Ethereum. They are used to automate various processes and transactions, including the transfer of assets and the enforcement of agreements. As such, they are an integral part of the growing blockchain ecosystem. However, like any other piece of software, smart contracts can contain bugs and vulnerabilities that can have serious consequences if exploited. This is why testing smart contracts is so important.

Vulnerabilities in smart contracts can cause loss of funds & damage the reputation of a protocol. Flaws in smart contract are easy targets for Hackers. Ever since the DAO hack billions have been lost to smart contracts exploits. Here’s where smart contracts audits comes in, they’re critical for risk assessment and mitigation strategies. An audit analyses the code to discover possible errors, security vulnerabilities, and recommend fixes before deployment. Let’s dive further into this added security layer and its structure.

Transcript of Bettina Warburg's talk at the TEDSummit, June 2016. Made available on the permaweb.

Whether you’re a web3 enthusiast or not, you’ll come across the term EVM if you haven’t already. The Ethereum Virtual Machine (EVM) is the underlying infrastructure of the Ethereum Blockchain. It allows developers to deploy smart contracts and build dApps (decentralized applications). How? Well, that’s what we’re about to dive into. Buckle up because it’s going to be a hell of a (technical) ride.