The HyperCarte research group wishes to offer a new cartographic tool for spatial analysis of social data, using the potential smoothing method. The purpose of this method is to view the spreading of phenomena's in a continuous way, at a macroscopic scale, basing on data sampled on administrative areas. We aim to offer an interactive tool, accessible via the Web, but guarantying the confidentiality of data. The major difficulty is induced by the high complexity of the calculus, working on a great amount of data. We present our solution to such a technical challenge, and our perspectives of enhancements.