In this paper, a subject-centric structure is proposed that improves the holder-centric structural problems of verifiable credentials developed for self-sovereign identities. Holder-Centric structured verifiable credentials represent a structure in which a holder can control the credentials even if it is not a subject. This structure allows the holder to attempt authentication or transfer credentials without the subject's permission. The subject may lose some control over the credential, thus losing the meaning of self-sovereign identity. We propose a subject-centric structure that allows the subject to control over the transferred verifiable credentials.
ACKNOWLEDGMENT This research was supported by \u201cBasic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology(2018R1D1A1B07048697)\u201d, \u201cKorea Institute for Advancement of Technology(KIAT) grant funded by the Korea Government(MOTIE) (P0008703, The Competency Development Program for Industry Specialist)\u201d, and \u201cthe MSIT(Ministry of Science and ICT), Korea, under the ITRC(Information Technology Research Center) support program(IITP-2020-2018-0-01396) supervised by the IITP(Institute for Information & Communications Technology Planning & Evaluation)\u201d.
