Recent technological progresses made it possible for complementary and community currencies to be increasingly transformed into digital currencies. An increasing number of them run on blockchain, a technology that allows for greater decentralization and trust-less systems. This fusion between social and cryptocurrencies opens a series of questionings: can social currencies maintain their values regarding the creation of community and a fuller citizenship? Is the total decentralization an important value for the communities that use social currencies? Can "trust", as defined for these monetary systems be replaced by a system that presupposes it? These comprehensive questions conform our current research project. With an inductive and multidisciplinary plan of demonstration in mind, this particular document tries to put in discussion the characteristics and potentialities, as well as the problems, limits and tensions generated by the circulation of digital currencies that run on Blockchain (cryptocurrencies), leaving for future research the in-depth discussion that this new mixture of technologies brings up. These issues will be addressed by studying the case of a digital social currency system running on blockchain, based on mutual credit, implemented in Argentina today: MonedaPAR, which was conceived as a defense mechanism against the economic crisis that plagues Argentina since 2016.