Authentication

 Once users have declared their identity, it becomes essential to confirm that they indeed possess the legitimate ownership of that identity. This procedure, involving the confirmation or substantiation of a user's identity, is commonly referred to as authentication. To put it simply, authentication is the method by which the requester's identity is substantiated.

Authentication typically employs one of three widely used approaches:

Something you know: This pertains to the use of passwords or passphrases, where users authenticate themselves based on knowledge-based information.

Something you have: This method involves the use of items such as tokens, memory cards, or smart cards as a means of authentication. Users prove their identity by presenting these physical items.

Something you are: In this approach, authentication relies on biometric data, which comprises measurable and unique physical or behavioral characteristics possessed by the individual, ensuring their identity is validated.