Authentication is widely used to protect consumer data and computing services, such as email, document storage, and online banking. Current authentication models, such as those employed by online identity providers, may have limited options and configurations for authentication schemes. Accordingly, as provided herein, a model based authentication scheme may be configured based upon a policy and/or an authentication mechanism list. The policy may define the target resource, a user, a group the user belongs to, devices used to connect to the target resource, a service owning the target resource, etc. The authentication mechanism list may comprise predefined authentication mechanisms and/or user plug-in authentication mechanisms (e.g., user created authentication mechanism). Once the authentication scheme is configured, it may be enforced upon authentication requests from a user. Feedback may be provided to the user based upon patterns of usage of the target resource.