00349nas a2200097   4500000000100000008004100001260008600042100001400128245006400142490004500206       2005                            d  cDecember 2005bNational Chiao Tung UniversityaHsinChu, Taiwan, Republic of China1 aI-Te Chen00aStudies on Proxy Signatures with/without Proactive Property0 vDoctor of Philosophy in Computer Science