Certificate Types

Question 1

Root Certificate

Answer 1

A root certificate is the first certificate that a Certificate Authority (CA) creates. It is the top-level certificate. They are self-signed by the CA and are used to sign lower-level certificates such as intermediate certificates.

Question 2

Subject Alternative Name (SAN) Certificate

Answer 2

SAN certificates allow an organization to cover multiple domains with one certificate. For example, TestOut could cover the following domains in a single SAN certificate:
- TestOut.com
- TestOut.net
- LabSim.com

Multiple domains with one certificate.

Question 3

Wildcard Certificate

Answer 3

Wildcard certificates are similar to SAN certificates. But instead of covering multiple domains, the organization can cover one domain and multiple subdomains. For example, TestOut could cover the following in one certificate:
- quiz.testout.com
- labs.testout.com
- videos.testout.com
- *.testout.com

One domain and multiple subdomains with one certificate.

Question 4

Code-Signing Certificate

Answer 4

Code-signing certificates are used by app developers to prove their application is legitimate.

If a user tries to run an app that does not have a certificate, they will receive an error stating that the app cannot be trusted. The user can decide to close the app or run it.

Question 5

Self-Signed Certificate

Answer 5

Self-signed certificates are certificates that have not been validated or signed by a CA, are easy and free to make, and do not provide the same protection and security as a CA-validated certificate.

When a user visits a website using a self-signed certificate, they see a warning that the certificate is not trusted.

Question 6

Email Certificate

Answer 6

Secure, encrypted emails are sent using the S/MIME Protocol.

Senders need to know the recipient’s public key when sending a secure email. The public key is found in email certificates.

Email certificates are mainly used in an organization that uses its own CA. However, some public CAs provide email certificates as well.

Question 7

User and Computer Certificate

Answer 7

User and computer certificates are used in a network environment to identify and validate specific users or computers.

When a user or computer logs into a network, their certificate is sent to the server for validation. This provides extra security to the network.

Question 8

Certificate Fields

Answer 8

A certificate also contains fields for: Organization (O); Organizational Unit (OU); Locality (L); State (ST); Country (C).

These are concatenated with the common name to form a Distinguished Name (DN).

For example: Example LLC’s DN could be: CN=www.example.com, OU=Web Hosti