Authentication (noun)

1. The act of confirming the authenticity of something, such as a person's identity, or the validity of data.
2. The process of proving that something is real, legitimate, or genuine.

Origin:

Derived from the greek word 'authentikos' meaning 'real, genuine, or trustworthy'.

Examples:

1. The authentication process requires a valid government-issued ID and a password.
2. The authentication of the painting was done by a team of experts.
3. Without proper authentication, sensitive information can easily fall into the wrong hands.
4. The authentication system is designed to prevent unauthorized access.
5. Many online transactions require a two-factor authentication process for added security.