Signicat's Email OTP is a simple identification method based on one-time passwords (OTP) sent by email. This is a typical scenario:
A user accesses a service that requires some sort of identification.
A merchant sends an email with an OTP code to the user.
The user enters the received code in the merchant's application.
The merchant receives the user's email in the response from Signicat
Although this method alone does not provide a high level of security, from a technical standpoint there is nothing that prevents a merchant from using Email OTP as a standalone authentication method. However, it is more common and recommended to use this method to boost an existing login process. Email OTP integrated with any username/password login solution will form a two-factor authentication method.