Anonymous Bitcoin Mixing Scheme Based on Semi-Trusted Supervisor

As Bitcoin users grow, the protection of the Bitcoin privacy protection becomes an important issue. Bitcoin mixing technology can cut off the connection between buyers and sellers. Now, a more effective method is used to carry out a coin mixing operation. The existing flat structure and two-layer structure have their own deficiencies. Therefore, anonymous Bitcoin mixing scheme is proposed. In order to increase the anonymity of coin mixing, group blind signature technology is used to expand the anonymous set of users. Moreover, a Supervisor for supervising Mixes is introduced to ensure the security of the system and the threshold signature is also used to ensure the security of the Mix’s Bitcoin to prevent the Supervisor from stealing Bitcoin. Finally, the security analysis and experiment are given to conclude that our scheme is secure and efficient.