Which of the following authentication methods provides credentials that are only valid during a
single session?

A.
Kerberos v5

B.
Smart card

C.
Certificate

D.
Token

Explanation:
Token method of authentication provides credentials that are only valid during a single
session. Token is a unique identifier, which is
generated and sent from a server to a software client to identify an interaction session.
Answer option C is incorrect. A certificate is a set of data that completely identifies an entity. It is a
digitally signed statement that binds the
value of a public key to the identity of a person. It can be issued to perform a number of functions
such as Web server authentication, secure
e-mail, etc. A certificate is valid only for the period of time specified within it. Moreover, a user can
set the duration for a certificate’s validity.

After the validity period, the certificate becomes invalid. A certificate also eliminates the need for
hosts to maintain a set of passwords for
individuals who are required to be authenticated.
Answer option B is incorrect. A smart card is a credit card-sized device used to securely store
personal information such as certificates, public
and private keys, passwords, etc. It is used in conjunction with a PIN number to authenticate users.
In Windows, smart cards are used to
enable certificate-based authentication. To use smart cards, Extensible Authentication Protocol
(EAP) must be configured in Windows.
Answer option A is incorrect. Kerberos v5 is an authentication method used by Windows operating
systems to authenticate users and
network services. Windows 2000/2003 and XP clients and servers use Kerberos v5 as the default
authentication method. Kerberos has
replaced the NT LAN Manager (NTLM) authentication method, which was less secure. Kerberos uses
mutual authentication to verify both the
identity of the user and network services. The Kerberos authentication process is transparent to the
users.
Note: Kerberos v5 is not supported on Windows XP Home clients or on any clients that are not
members of an Active Directory domain.