可监管的区块链匿名交易系统模型

针对现有区块链系统可追溯性与隐私保护难以兼顾的问题，设计了一种可监管的区块链匿名交易系统模型。首先，结合标识密码（IBC）和无证书公钥密码体制（CL-PKC）的优点，消除了单一IBC托管密钥带来的隐患，并在可保证安全条件下将用户交易标识与用户身份关联，从而保证了模型中的可监管性；其次，通过从网络层和应用层双层签名认证实现了隐私安全，既保证了用户交易内容和身份隐私的安全性，又确保权威机构能够根据异常交易进行追溯，从而为当下区块链匿名性和可监管性的兼容提供了一种新的思路；最后，把所提模型和自认证签名模型、多中心SM9模型及可追溯门罗币模型等进行对比，并通过计算机模拟仿真比较了所提模型和主流区块链模型的传输耗时。实验结果表明，所提模型在安全性和可追溯性上有较大优势；在相同软硬件环境下，多次传输相同大小信息时，所提模型的信息传输耗时比以太坊模型多168%，而长时间传输情况下效率差距不大；传输不同长度的信息时，所提模型的平均耗时要比以太坊模型多38%。

Supervisable blockchain anonymous transaction system model

In order to solve the problem that the traceability and privacy protection of the existing blockchain systems are difficult to balance， a supervisable blockchain anonymous transaction system model was designed. Firstly， the advantages of Identity-Based Cryptograph （IBC） and Certificateless Public Key Cryptography （CL-PKC） were combined to remove the hidden dangers caused by the single IBC key escrow， and the user transaction identification was associated with the user identity under safe conditions， thereby ensuring the supervisability of the model. Then， privacy security was achieved through double-layer signature authentication from the network layer and the application layer， which not only guaranteed the security of users’ transaction content and identity privacy， but also ensured that the authority was able to trace back based on abnormal transactions， providing a new idea for the compatibility between the current blockchain anonymity and supervisability. Finally， the proposed model was compared with the self-certified signature model， the multi-center SM9 model and the traceable Monero model， and the transmission time consumptions of this model and the mainstream blockchain systems were compared by computer simulation. Experimental results show that the proposed model has greater advantages in security and traceability； under the same hardware and software environment， the proposed model consumes 168% more time than the Ethereum model when transmitting the same size information for several times， and the difference in efficiency is not significant in the case of long-time transmission； the proposed model consumes 38% more time than the Ethereum model on average when transmitting information of different lengths.