(alpha, k)-anonymity: an enhanced k-anonymity model for privacy preserving data publishing

Abstract

Privacy preservation is an important issue in the release of data for mining purposes. The k-anonymity model has been introduced for protecting individual identification. Recent studies show that a more sophisticated model is necessary to protect the association of individuals to sensitive information. In this paper, we propose an (alpha, k)-anonymity model to protect both identifications and relationships to sensitive information in data. We discuss the properties of (alpha, k)-anonymity model. We prove that the optimal (alpha, k)- anonymity problem is NP-hard. We first present an optimal global recoding method for the (alpha, k)-anonymity problem. Next we propose a local-recoding algorithm which is more scalable and result in less data distortion. The effectiveness and efficiency are shown by experiments. We also describe how the model can be extended to more general cases.