All concepts
Concept
Precursor
DigiCash / ecash
First appeared Jan 1990
Why it matters
DigiCash proved private electronic cash was possible and then failed for the exact reason Bitcoin set out to fix: it needed a trusted company at the center. Its collapse defined the problem.
What it is
David Chaum's 1990s digital cash, built on his blind-signature cryptography to give users real payment privacy. It worked — but depended on Chaum's company as a central issuer, and DigiCash went bankrupt in 1998.