Mikaela works for a financial services company and wants to register customers for her web application. What type of authentication mechanism could she use for the initial login if she wants to quickly and automatically verify that the person is who they claim to be without having a previous relationship with them?

Knowledge-based authentication is used by some financial institutions to validate the identity of new users. It uses information from tax and financial records that is unlikely to be available to others, allowing new users to provide details like their last credit card payment, mortgage payment, or other information to validate their identity. A Social Security number is somewhat trivial to acquire via paid services or other means, and manually validating identities is neither quick nor automatic. A biometric factor would require a previous enrollment, making this unsuitable for new customers.