A normal approximation for joint frequency estimatation under Local Differential Privacy

In the recent years, Local Differential Privacy (LDP) has been one of the corner stone of privacy preserving data analysis. However, many challenges still opposes its widespread application. One of these problems is the scalability of LDP to high dimensional data, in particular for estimating joint-distributions. In this paper, we develop an approximate estimator for category frequency joint-distribution under so-called pure LDP protocols.