Authentication system and authentication method

An authentication system configured to authenticate a user for entering a specific area or using a specific service provided in the specific area, the authentication system comprising:

• one or more memory devices configured to store a consent status of the user for one or more consent matters, which are needed in the specific area or when using the specific service;
• one or more processors;
• and
• a communication terminal operated by the user, wherein
• the one or more processors are configured to execute:
• a consent confirmation process of accepting consent to the one or more consent matters from the user via the communication terminal;
• an update process of updating the consent status depending on whether or not there is the consent;
• and
• an authentication process of permitting the user to enter the specific area or to use the specific service on condition that there is the consent, and
• the consent confirmation process includes:
• a detection process of detecting exit of the user from the specific area;
• and
• a withdrawal confirmation process of accepting a withdrawal of the consent from the user via the communication terminal at a time of the exit.