Buying and selling things with cryptocurrencies is hard. Every time you make any transaction, it's recorded in the blockchain, a digital ledger. That takes up a ton of resources, such as hard drive space. But a new technology called the Lightning Network could offer a way to speed up the process. It's a huge change in how cryptocurrencies could work. Marketplace Tech host Molly Wood spoke about it with Timothy Lee, a reporter at the tech news site Ars Technica.