Abstract: An authentication system for authenticating a user to access gated digital content includes a user computing device, a service provider server, an authentication service, and at least one identity provider. The service provider server is configured to require registration and authentication prior to providing the user with access to the gated digital content, and the at least one identity provider is configured to authenticate a user identity of the user. Upon receiving a request via the user computing device to access the gated digital content hosted by the service provider server, the authentication service displays an authentication platform interface to the user. The authentication platform interface displays at least one identity provider selector linked to the at least one identity provider, and the at least one identity provider is based on a policy of the authentication service set by the service provider.