CompTIA Security Plus Mock Test Q882

Which of the following authentication services uses a ticket granting system to provide access?

D. Kerberos

Correct Answer: D
Section: Access Control and Identity Management

The basic process of Kerberos authentication is as follows:
The subject provides logon credentials.
The Kerberos client system encrypts the password and transmits the protected credentials to the KDC.
The KDC verifies the credentials and then creates a ticket-granting ticket (TGT—a hashed form of the subject’s password with the addition of a time stamp that indicates a valid
lifetime). The TGT is encrypted and sent to the client.
The client receives the TGT. At this point, the subject is an authenticated principle in the Kerberos realm.
The subject requests access to resources on a network server. This causes the client to request a service ticket (ST) from the KDC.
The KDC verifies that the client has a valid TGT and then issues an ST to the client. The ST includes a time stamp that indicates its valid lifetime.
The client receives the ST.
The client sends the ST to the network server that hosts the desired resource.
The network server verifies the ST. If it’s verified, it initiates a communication session with the client. From this point forward, Kerberos is no longer involved.

Incorrect Answers:
A: Radius does not make use of tickets.
B: The Lightweight Directory Access Protocol (LDAP) is an open, vendor-neutral, industry standard application protocol for accessing and maintaining distributed directory information
services over an Internet Protocol (IP) network.
C: TACACS+ makes use of Kerberos as an authentication mechanism.

Stewart, James Michael, CompTIA Security+ Review Guide, Sybex, Indianapolis, 2014, pp. 270-274