Lin, Zi2012-09-202012-09-202012-07https://hdl.handle.net/11299/133924University of Minnesota Ph.D. dissertation. July 2012. Major: Computer science. Advisor:Prof. Nicholas Hopper. 1 computer file (PDF); ix, 107 pages.en-USAnonymityPrivacy-enhancingWatermarkComputer ScienceThesis or Dissertation