A Security Mechanism Based on Uniform Rounding to Prevent Tracker Techniques

In the last decade powerful snooping tools like the tracker have been developed, with which a questioner is able to deduce confidential information about individuals by processing statistical queries. In the first section of this paper we discuss a security mechanism based on Bernoulli experiments. Experimental results show that although this method has good statistical properties the relative errors of the estimators are high. The idea of exclusion resp. multiple inclusion of individuals (belonging to the specified query set) together with uniform rounding leads to a security mechanism with small relative errors. However, the statistics are no longer unbiased, so small query set compromise and trackers are no longer possible.