Bitcoin Mix System Design Based On Partial Blind Signature

Electronic cash theory is a very important direction in electronic payment system research field. Bitcoin as the first widely accepted electronic cash, make sense for promoting the development of electronic commerce. For Bitcoin, anonymity is one kind of characteristics, but it belongs to the pseudo anonymous, through the transaction data analysis and other methods could weak its anonymity; Decentralized is the other kind of characteristics,but as it lack of effective management that may cause a variety of security problems.For the anonymous security and regulatory problems, corresponding solutions are designed in this paper. For the first problem, a security enhancement scheme is proposed in this paper, which a mix agent added in the original Bitcoin system, and a new electronic cash mix algorithm based on RSA blind signature is proposed, this scheme could effectively improve the anonymous security of Bitcoin; secondly, based on the new mix algorithm, a trusted third party were introduced, a revocable user anonymity scheme is proposed and puts forward a centralized trading agent release technology based on Concrete Symmetric encryption algorithm、hash algorithm and digital signature algorithm. In order to build reliable electronic cash system, and make further improved of the privacy security level of the Bitcoin system. Finally, simulation experiment and systematic design demonstrate the correctness and rationality of scheme.Compared with other existing Bitcoin mix systems, this scheme has the following advantages. First, this paper introduces the trust third party, not only reduces the sources for maintenance of system security, but also reduces transaction confirmation waiting time, and enables users avoid of high risk of unsafe mix service center. Second, the used of partially blind signature algorithm could improve anonymity of system. Third, the underlying system protocol is compatible with Bitcoin system. Last, the design of revocation scheme has advantage to supervision Bitcoin.