Bitcoin – in the beginning
Money has not had a major innovative disruption in at least several decades, but there have been many attempts in the past, such as DigiCash (Chaum, 1989), e-gold (Jackson and Downey, 1996), B-money (Dai, 1997), bit gold (Szabo, 1998), and Liberty Dollar (von NotHaus, 1998). It wasn't until the invention of bitcoin that a disruption really started to show, but why did these previous attempts fail?
DigiCash
One of the biggest challenges in creating a cryptocurrency is the double-spend problem. This is where the same digital currency is spent twice because it can be easily copied in the digital realm. In fact, it can be spent many times over.
In 1982, David Chaum, an American computer scientist and cryptographer, published a paper on his idea of Blind Signatures for Untraceable Payments (http://www.hit.bme.hu/~buttyan/courses/BMEVIHIM219/2009/Chaum.BlindSigForPayment.1982.PDF). Then, in 1988, he co-authored a paper on Untraceable Electronic Cash (http...