What is considered the most common form of authentication?

The most common form of authentication is passwords. Passwords have been widely utilized for many years in various systems and applications as a primary means to verify the identity of users. They are easy to implement and require minimal infrastructure, which contributes to their prevalence.

While digital certificates, biometrics, and smart cards provide robust security features, they often require more complex implementations, such as specialized hardware or software, which can hinder their widespread adoption. Passwords are familiar to users and can be modified easily, making them a convenient choice for securing accounts and access to sensitive information. Additionally, they can be integrated into numerous platforms, from personal email accounts to corporate systems, reinforcing their status as the most common form of authentication.