Abstract: This paper mainly focuses on the mean estimation problem in differential privacy query.After introducing the current mainstream local differential privacy design scheme of numerical data mean estimation,it first introduces the random censoring mechanism in random response technology to reveal the basic principle of mean calculation under local differential privacy,proposes a utility optimization theorem about the variance of mean estimation,and gives a boundary optimization formula,which improves the interpretability and operability of utility optimization theory in this field.Based on this theory,this paper proposes a practical,concise and efficient mean estimation algorithm protocol RCP for the first time,which can be used to collect and analyze the data of intelligent device users connected to the Internet,while meeting the requirements of local differential privacy.RCP is simple in structure,supports data analysis tasks on any number of numerical attributes,and has efficient communication and calculation,effectively alleviating the practical problems of complex algorithm design,difficult optimization,and low efficiency.Finally,empirical research demonstrates that the proposed method outperforms other existing schemes in terms of utility,efficiency and asymptotic error bounds.

Key words: Local differential privacy, Mean estimation, Random response, Random censoring, Utility optimization