An Information-Theoretic Approach to Individual Sequential Data Sanitization

Fine-grained, personal data has been largely, continuously generated nowadays, such as location check-ins, web histories, physical activities, etc. Those data sequences are typically shared with untrusted parties for data analysis and promotional services. However, the individually-generated sequential data contains behavior patterns and may disclose sensitive information if not properly sanitized. Furthermore, the utility of the released sequence can be adversely affected by sanitization techniques. In this paper, we study the problem of individual sequence data sanitization with minimum utility loss, given user-specified sensitive patterns. We propose a privacy notion based on information theory and sanitize sequence data via generalization. We show the optimization problem is hard and develop two efficient heuristic solutions. Extensive experimental evaluations are conducted on real-world datasets and the results demonstrate the efficiency and effectiveness of our solutions.