Recently IT infrastructure plays a central role in the base of the society. However, use of personal registration number on internet sites has become a major factor increasing danger of leaking of personal information. Currently, the government is recommending various information protection services in order to prevent the collection of personal registration numbers and leaking of personal information on the internet. Among them, i-PIN service is the one recommended for minimal use of personal registration numbers on the internet. Although i-PIN can be used as a way to substitute personal registration numbers on the internet, there are certain limitations in using i-PIN as the only key to recognize individuals. This study proposes organization of web system in which self certification can be conducted using i-PIN as a tool for personal certification. Also its usability and stability have been verified through performance test when i-PIN service is linked with web service and used as personal certificate. But i-PIN service is unavailable if obstacles occur in providers of i-PIN self certification. To settle this inconvenience, the study also proposes how to cope with such obstacles.