section we provide a brief overview of the historical context in which crypto-currencies have emerged. We touch upon government-backed and commodity backed currency and discuss the development of cryptographic protocols that enabled e-money. Finally, we describe the online communities which were first exposed to virtual currency and the differences between the aforementioned forms of money and crypto-currency.

Fiat currency and e-money
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We start with a brief definition of a fiat currency. The European Central Bank defines fiat currency as any legal tender designated and issued by a central authority that people are willing to accept in exchange for goods and services because it is backed by regulation, and because they trust this central authority. Fiat money is similar to commodity backed money in this regard with respect to its usage, but differs in that it cannot be redeemed for a commodity, such as gold. The most common form of fiat currency backing is at the sovereign state’s government level, but there have also been localised currencies or private monies, see discussion in [@peters2014opening] for their use in local communities in the UK and Germany.

While one is most commonly accustomed to thinking about money in its physical form, only 