基于隐私保护的法定“数字货币”激励机制

Truthful incentive mechanism for “digital currency” based on privacy protection

多国央行已开展基于分布式账本技术的法定"数字货币"研究,唯有英国公开了法定"数字货币"框架RSCoin的交易记账架构,并设计激励机制鼓励授信机构提供协作记账服务。但是,RSCoin中的激励机制没有考虑授信机构差异性的服务成本,也没有给出明确的报酬分配方案。充分考虑授信机构差异性的隐私成本,建立央行和授信机构的激励模型,明确授信机构的报酬,首次提出一种既保护授信机构隐私成本又保证授信机构诚实报价的激励机制POPTIM。POPTIM首先通过编码散列方法对授信机构的协作报价进行加密;然后基于隐私保护排序算法选择待支付的授信机构;最后基于同态加法算法计算各授信机构获得的报酬。通过理论分析可知,POPTIM机制具有隐私安全、计算高效、满足授信机构个体理性和保证授信机构诚实报价的性质。

Many national central banks have conducted legal digital currency research based on distributed ledger technology,but only the UK has disclosed the accounting structure of the legal digital currency framework RSCoin,and the incentive mechanisms was proposed to encourage mintettes to provide honest collaborative accounting services.However,this mechanism does not take into account the differential service costs of mintettes,nor does it give a definite compensation distribution.The privacy costs of the mintettes were fully considered,the incentive model of the central bank and mintettes were established,and the methods were clarified to compensate mintettes.In the legal digital currency research area,an incentive mechanism POPTIM was proposed firstly,that not only protects the private cost of the mintettes,but also guarantees the mintettes report their truthful bidding prices to the central banks.POPTIM first encrypts the biddings of mintettes by coding hash encryption method,then adopts privacy-preserving sorting algorithm to select the winner mintettes,and finally calculates the reward of mintettes based on the homomorphic addition algorithm.The analysis shows that the mechanism is privacy security,computationally efficient,individually rational and truthful simultaneously.