CompTIA CASP+ Practice Test

What role does a digital signature play in email security?

1. Ensures authenticity and integrity of the email

2. Increases email delivery speed

3. Eliminates the need for encryption

4. Acts as a spam blocker

The correct answer is: Ensures authenticity and integrity of the email

A digital signature plays a crucial role in email security by ensuring both the authenticity and integrity of the email. When an email is digitally signed, it involves the use of a public key infrastructure (PKI) where the sender's private key creates a unique digital signature for the email message. This signature verifies that the message was indeed sent by the claimed sender, preventing impersonation or spoofing. If any part of the email is altered after it has been signed, the digital signature becomes invalid, indicating that the message has been tampered with. In terms of functionality, a digital signature provides assurance to the recipient that the content has not been modified in transit and that it originates from the legitimate sender. While this contributes to overall security, it does not relate to the speed of email delivery, nor does it eliminate the need for other security practices such as encryption. Furthermore, a digital signature does not serve the purpose of blocking spam; its primary focus is on validating the identity of the sender and protecting the message's content.