David Chaum, the inventor of eCash and CEO of xx network, and Adam Back, the inventor of Hashcash and the cofounder and CEO of Blockstream, discuss their involvement in digital currency well before Bitcoin existed. In this episode, they discuss:

how they each became enamored with the idea of digital currency years before such an idea was widely discussed
the crypto wars of the 1990s and the U.S. government’s attempts to control access to advanced cryptography
Digicash, the creation of eCash, and the difficulties of implementing the system with the technology available at the time
the innovation of blind signatures used in eCash
what caused the demise of Digicash, and David's role in that
the development of Hashcash and the problems Adam was trying to solve by creating it
their initial reactions to learning about Bitcoin for the first time
how they think Bitcoin might improve in the future
the stock-to-flow Model, and where they believe the Bitcoin price might go next
why the Hashcash proof-of-work mechanism became so widely used