Bitcoin Trust Communities.

Cryptocurrency exchange platforms, which have appeared recently, provide exchanges between different types of cryptocurrencies as well as fiat money. Since multiple exchange platforms exist today, it is of essential importance to have timely information about user experience and the behavior of participants in such platforms. Trust is a notion that has been studied extensively in sociology, psychology, economics and compuer science, with an objective to provide measures for quantifying user behavior in specific social settings and contexts. While in the domain of online social networks, the trust has been thoroughly analyzed from various points of view, in cryptocurrency exchange platforms, the questions about quantifying the levels of emerging trust, are still open. In this work, we elaborate on quantifying trust in the context of cryptocurrency exchange platforms. We focus on two well known bitcoin exchange platforms: Bitcoin-OTC and Bitcoin-Alpha. Using the existing data about user ratings upon interactions in these two platforms, we show how trust is related with the network structure and how to identify communities where trust level is high among participants. Our results can serve as a basis for a strategy on how to interact within these platforms.