Privacy-aware data management by means of data degradation : making private data less sensitive over time

Dit proefschrift is goedgekeurd door de promotoren: The text depicted on the cover of this book is an arbitrary selection of queries taken from the query log disclosed by aol in 2006 [52]. As such, the content of the queries does not represent the personal view of the author. Acknowledgments This thesis could not have been completed without the excellent supervision of both my French and Dutch supervisors, and the help from and discussions with many colleagues and friends. Therefore I want to acknowledge the following people. First of all, I want to thank Nicolas for working together on data degradation since I was a master student at the University of Twente in 2005. Thanks to him I could experience working at INRIA in France, resulting in a cotutelle de thèse. We have had many excellent discussions, making travelling to Paris always worth the effort, and boosting the progress I made in my research. I also want to thank Philippe and Luc; I always looked forward to discuss the work with them, since the input they gave improved the work significantly. Second, I want to thank Maarten, who was always available to listen to new ideas and gave those ideas a—formal—shape. His support and the discussions we had—which always took three times longer than planned— were of great value for me, as were the monthly discussions with Peter. Beside the people I already mentioned, I want to thank all my colleagues of the database group who provided a great and pleasant working environment. We have had a lot of fun and many nice conversations, not only when we visited conferences and workshops together, but also during lunches and the 'groepsuitjes'. Special thanks go to Ida, who was always there to help and talk with, and Riham, who became a great friend with whom I had pleasant conversations and lunches, and made that I didn't loose confidence in my research. Special thanks go to Berteun who helped me a lot with all the formatting of my thesis; Berteun's L A T E X skills are indeed unrivaled, which saved me a lot of time and frustration. Finally I conclude with thanking my friends and family, especially my parents, for all their support during all those years.