This study examines the digital transformation of higher education in Japan, focusing on the digitalization of university-issued certificates. Although digital certificates improve efficiency, security, and tamper resistance, adoption has been hindered by cultural, technical, and legal barriers. To address these challenges, we analyzed institutional certificate data and defined 21 standardized attributes consistent with Japanese notation and international schema standards. Building on these definitions, we propose an architecture that separates the roles of the Identity Provider (IdP) and Attribute Provider (AP), enabling secure and flexible attribute delivery to Service Providers (SPs). Two approaches for AP referencing—SP-side storage and user wallet distribution—are discussed. A prototype developed in 2024 demonstrated the feasibility of digital enrollment certificate issuance and its application to student discount services. This work contributes to the domestic standardization of attribute information and the establishment of a trust framework for next-generation digital academia.