Strong authentication helps to prove or confirm one’s identity so the right user has access to the resource in question. Username and passwords were the stepping stone in providing access or authenticating a user, but with phishing attacks and data breaches, authentication needed to be complex to secure the user as well as the resource. Therefore authentication needs to be more robust and provide additional factors to increase security. These factors can be a knowledge factor, ownership factor, or an inherence factor. Examples would include a password, pin (knowledge factor), phone or security token (ownership factor) or biometrics (inherence).
Strong authentication could take the form of Multi-factor authentication or Adaptive authentication.