At about 11 minutes in the video he mentions cryptocurrency being used as a means for buying goods and services with gold and silver. The term cryptocurrency is not accurate here, as cryptocurrency specifically refers trading vehicles whose only purpose is for speculation and not for use as a real currency, such as Bitcoin and the like, because they are self perpetuating through the use of blockchain mining. What he is talking about here would be more properly referred to as digital currency. While both of these use blockchain at their core, such a digital currency would make the proper intended use of blockchain, which is simply the purpose of verifying authenticity without the need for third-party verification, and the actual amount of digital currency in such a system would have to match exactly the amount of gold and silver represented by that digital currency, with that process of verification serving the dual purpose of verification and creating new digital currency that is actually represented by physical gold and silver.