Patent attributes
An authentication system is provided with: a user device; user side assistance device(s) to assist user authentication that authenticates a user of the user device, and apparatus authentication that authenticates the user device; and an apparatus authentication server device to perform apparatus authentication in association with the user device. The user side assistance device(s) use distributed shares of verification information to perform multi-party computation for user authentication in association with the user device, and use distributed shares of a secret key generated by the user device, to perform multi-party computation for apparatus authentication in association with the user device.