  Numerous electronic cash schemes have been proposed over the years - however
none have been embraced by financial institutions as an alternative to fiat
currency. David Chaum's ecash scheme was the closest to something that mimicked
a modern day currency system, with the important property that it provided
anonymity for users when purchasing coins from a bank, and subsequently
spending them at a merchant premises. However it lacked a crucial element
present in current fiat-based systems - the ability to continuously spend or
transfer coins. Bitcoin reignited the interest in cryptocurrencies in the last
decade but is now seen as more of an asset store as opposed to a financial
instrument. One interesting thing that has come out of the Bitcoin system is
blockchains and the associated distributed consensus protocols. In this paper
we propose a transferable electronic cash scheme using blockchain technology
which allows users to continuously reuse coins within the system.
