DigiCash

DigiCash is one of the early attempts at digital currency. Like the current-day digital currencies of the Bitcoin vein, it made use of cryptographic protocols to anonymize transactions, but unlike those (and like most early e-currencies) it was based around a central institution, and hence vulnerable to going away if that institution went belly-up, as in fact happened when they went bankrupt in 1998. The remnants of it were acquired by ecash.

Links

 * Wikipedia article