Annually sponsored by the Korea Institute of Information Security and Crypt- ogy (KIISC), the fourth International Conference on Information Security and Cryptology (ICISC2001) was held at the 63 Building in Seoul, Korea, Dec- ber 6–7, 2001. The 63 Building, consisting of 60 stories above the ground and 3 stories underground, stands soaring up into the sky on the island of Youido, the Manhattan of Korea, and ranks by far the tallest of all buildings in the country. The program committee received 102 submissions from 17 countries and regions (Australia, Belgium, China, Denmark, France, Germany, India, Italy, Japan, Korea, The Netherlands, Spain, Taiwan, Thailand, Vietnam, UK, and USA), of which 32 were selected for presentation in 8 sessions. All submissions were anonymously reviewed by at least 3 experts in the relevant areas. There was one invited talk by David Pointcheval (ENS, France) on “Practical Security in Public-Key Cryptography”. We are very grateful to all the program committee members who devoted much e?ort and valuable time to reading and selecting the papers. These p- ceedingscontainthe?nalversionofeachpaperrevisedaftertheconference.Since the revised versions were not checked by the program committee rigorously, the authors must bear full responsibility for the contents of their papers.