Authentication in Hadoop can either be simple or in Kerberos. Hadoop also allows you to have your custom authentication scheme. In this section, we will look at Kerberos authentication and how the HTTP Hadoop interfaces can be secured via authentication.
Kerberos is a network authentication protocol. It uses cryptography to provide a highly secure authentication mechanism. This authentication mechanism is popular because of its features, which are as follows:
Mutual authentication: Both the client and server can mutually authenticate each other before proceeding with a session.
Single login per session: Once a login happens, tokens with certain time validities are issued for usage. The duration of token validity defines the maximum length of the session.
Protocol message encryption: All protocol messages during authentication are encrypted. It is not possible to conduct any man-in-the-middle or replay attacks by an adversary.