Anonymous Methods Based on Multi-Attribute Clustering and Generalization Constraints

Abstract

The dissemination and sharing of data sheets in IoT applications presents privacy and security challenges that can be addressed using the k-anonymization algorithm. However, this method needs improvement, for example, in areas related to its overgeneralization and its insufficient attribute diversity constraints during the anonymization process. To address these issues, this study proposes a multi-attribute clustering and generalization constraints (k,l)-anonymization method that can be applied to multidimensional data tables. The algorithm first used a greedy strategy to rank the attributes by width first, derived the division into dimensions to construct a multidimensional generalization hierarchy, and then selected the attributes with the most significant width values as the priority generalization attributes. Next, the k-nearest neighbor (KNN) clustering method was introduced to determine the initial clustering center by the width-first results, divide the quasi-identifier attributes into KNN clusters according to a distance metric, and generalize the quasi-identifier attributes in the equivalence class using a hierarchical generalization structure. Then, the proposed method re-evaluated the attributes to be generalized before each generalization operation. Finally, the algorithm employed an improved frequency–diversity constraint to generalize sensitive attributes in order to ensure that there were at least l records that were mutually dissimilar and closest in the equivalence class. While limiting the frequency threshold for the occurrence of sensitive attributes, the sensitive attribute values remained similar within the group, thus achieving protection of anonymity for all the attributes.