Learn how to create Bitcoin and Ethereum transactions from scratch and deploy them yourself without a consumer wallet.
Double Spending and Replay Attacks
Learn to send the same Bitcoin to two different addresses at the same time. Also, learn how to reuse a previous transaction from one Ethereum blockchain on another.
Learn how to detect possible race conditions within web and mobile apps that could work in your favor to extract funds.
Meet your team and start understanding Bitcoin double spending, by double spending on this very site to get some Glass on the Ethereum network. Get an in depth understanding of how inputs, outputs, mining, and confirmations on the two most popular blockchains.
Before we start hacking a bunch of smart contracts, tokens, and blockchains in general, let's review their underlying technology. Here, we will cover Ethereum's popular contract language, Solidity. We will examine previously exposed hacks that allowed users to take over others' accounts via address phishing.
In order to hack technology, it helps to walk in the creators' shoes to see how easy it is to make mistakes. We will deploy basic contracts on the Ethereum blockchain and examine many of the common mistakes made by n00bs, including misplaced throw commands that can lock funds in contracts forever, even disallowing the owners to be able to retrieve funds.
Now that we've deployed a few contracts of our own, it's time to start trading contracts around hacking each other's code. We will discuss security measures that can be placed in contract creation, as well as how to craft transactions so that other accounts can abuse our transactions. Additionally, we will start spamming a few of the blockchains to slow down the general traffic in Bitcoin and Ethereum blockchains. In this last week of the class, we will each deploy our own cryptocurrency and blockchains.