Looking at the choices below, which ones would be the most suitable protocols/tools for securing e-mail?

A.
PGP and S/MIME

B.
IPsec and IKE

C.
TLS and SSL

D.
SSH

Explanation:
Secure MIME (S/MIME) is a standard for encrypting and digitally signing electronic mail and for providing
secure data transmissions.
PGP is often used for signing, encrypting, and decrypting texts, e-mails, files, directories, and whole disk
partitions and to increase the security of e-mail communications.
Incorrect Answers:
B: IPSec is not used to protect e-mails. IPsec is used to secure Internet Protocol (IP) communications by
authenticating and encrypting each IP packet of a communication session. IPSec can be implemented with the
help of the IKE security architecture.
C: SSL and TLS are primarily used to protect HTTP traffic.
D: SSH is not used to protect e-mails. SSH allows remote login and other network services to operate securely
over an unsecured network.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, pp. 850-851