Join Me on a Market for Anonymity
We present the first measurement study of JoinMarket, a growing marketplace for more anonymous transfers in the Bitcoin ecosystem. Our study reveals that this market is funded with multiple thousand bitcoins and generated a turnover of almost 8 million USD over the course of eight months. Assessing the resilience of the market against a wellfunded attacker, we discover that in a typical scenario, a selective attack with 90 % success rate requires an investment of 32,000 USD (which is recoverable after the attack). We formulate stylized economic models of supply and demand to explain the existence of this novel market for anonymity and underpin some theoretical arguments with empirical data.