Ecash was conceived by David Chaum as an anonymous cryptographic electronic money or electronic cash system in 1982. It was realized through his corporation Digicash and used as micropayment system at one US bank from 1995 to 1998.

The Genesis Files: How David Chaum’s eCash Spawned a Cypherpunk Dream

Bitcoin and other cryptocurrencies can trace their roots to this earlier, privacy-focused payment system for the internet.