He was reffering to a few attempts during the late 80's and 90s when the cypherpunk movement was gaining traction. Alot of people in the movement were trying to solve how a cryptographically implemented decentralized banking system could be created.
I wasn't even old enough at the time but I guess none of those attepts succedes it's porpuse. Bitcoin was the first cryptographic currency and wasn't even built in existing protocols. That's intresing though, I had no idea.