ISC2 Exam ISSAP Topic 5 Question 81 Discussion

password to each application. In SSO, a user can access all computer applications and systems where he has access permission without

entering multiple passwords. This reduces human error and systems failure and is therefore highly desirable. There are many commercial SSO

solutions available in the market. Some of them are as follows:

Central Authentication Service (CAS)

The Dutch NREN

CoSign

Enterprise Single Sign-On (E-SSO)

Web Single Sign-On (Web SSO)

Security Assertion Markup Language (SAML)

Direct SSO

Shibboleth

Answer option B is incorrect. A one-time password (OTP) is a password only valid for a single login session or transaction. OTP avoids a

number of shortcomings that are associated with traditional passwords. The most important shortcoming that is addressed by OTP is that OTP

is not vulnerable to replay attacks. If a potential intruder manages to record an OTP that was already used to log into a service or to conduct

a transaction, he will not be able to abuse it since it will be no longer valid.

Answer option D is incorrect. Kerberos is a secure protocol that supports ticketing authentication. A ticket is granted in response to a client

computer authentication request by the Kerberos authentication server, if the request contains valid user credentials and a valid Service

Principal Name (SPN). The ticket is then used by the client computer to access network resources. To enable Kerberos authentication, the

client and server computers must have a trusted connection to the domain Key Distribution Center (KDC). The task of KDC is to distribute

shared secret keys to enable encryption.

Answer option C is incorrect. In the dynamic password authentication scheme, passwords are changed after a specified time or time interval.