ABSTRACT
Authentication is a technique or mechanism to prove and validate an end user or a computer program's identity. People used to authenticate based on voice, a word or short, written documents, etc. In recent times, personal identification numbers, passports, driving licenses, and other IDs are used.
Computer authentication was created in the early 1960s to have an access control mechanism to share the limited computing resources of expensive mainframe computers. Authentication managed access control of the system by only allowing the users with access privileges.
To overcome the problems with legacy authentication methods, more sophisticated technologies were gradually invented, such as digital certificates, biometrics, access tokens, security keys such as Yubikeys (a USB device that generates a unique passcode) and Zukey (security token hardware). Today, a combination of personal identification numbers and security questions, passwords, etc., are used.
This chapter will explain authentication technologies, their advantages and disadvantages, and the different products, which use these technologies.
