CompTIA Security Plus Mock Test Q455

An encrypted message is sent using PKI from Sara, a client, to a customer. Sara claims she never sent the message. Which of the following aspects of PKI BEST ensures the identity of the sender?

A. CRL
B. Non-repudiation
C. Trust models
D. Recovery agents

Correct Answer: B
Section: Compliance and Operational Security

Explanation:
Non repudiation prevents one party from denying actions they carried out. This means that the identity of the email sender will not be repudiated.

Incorrect Answers:
A: CRLs are literally a list of certificates that a specific CA stated should no longer be used.
C: Trust models are used with PKIs. It is not used to ensure the identity of the email sender.
D: Recovery Agents are used with certificates.

References:
Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, 6th Edition, Sybex, Indianapolis, 2014, pp. 262, 414