Authentication system and authentication program

摘要

An authentication system (120), of another organization that is a different organization from a first organization to which a first user belongs, wherein a management device (200) accepts a registration transaction for a client certificate of the first user. The management device then registers the client certificate of the first user with a client certificate block chain. When the first user accesses a service of the other organization from a user terminal of the first organization, an authentication device (300) authenticates the first user by use of the client certificate of the first user in the client certificate block chain.