Which of the following relies on a physical characteristic of the user to verify his identity?

A.
Social Engineering

B.
Kerberos v5

C.
Biometrics

D.
CHAP

Explanation:
Biometrics is a method of authentication that uses physical characteristics, such as fingerprints,
scars, retinal patterns, and other forms of biophysical qualities to identify a user. Nowadays, the
usage of biometric devices such as hand scanners and retinal scanners is becoming more common in
the business environment.
Answer option B 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.
Answer option A is incorrect. Social engineering is the art of convincing people and making them
disclose useful information such as account names and passwords. This information is further
exploited by hackers to gain access to a user’s computer or network. This method involves mental
ability of the people to trick someone rather than their technical skills. A user should always distrust
people who ask him for his account name or password, computer name, IP address, employee ID, or
other information that can be misused.
Answer option D is incorrect. Challenge Handshake Authentication Protocol (CHAP) is an
authentication protocol that uses a secure form of encrypted authentication. Using CHAP, network
dial-up connections are able to securely connect to almost all PPP servers.