What type of certificate matches multiple subdomains under a parent domain?

What type of certificate matches multiple subdomains under a parent domain?

• A. Wildcard domain
• B. SAN
• C. CRL
• D. OCSP

Answer: (A)

Wildcard certificates secure many subdomains under a single parent domain by using a wildcard character in the domain field, typically in the form *.example.com. This means subdomains like shop.example.com, login.example.com, and api.example.com are covered by one certificate, simplifying management and reducing the need for separate certs for each subdomain. However, the wildcard usually covers only one level of subdomains and doesn’t automatically cover the root domain example.com unless that is included separately (often as a SAN). A SAN certificate, on the other hand, lists multiple exact hostnames (such as sub1.example.com, sub2.example.com) but doesn’t automatically cover all subdomains under a parent—you’d have to enumerate each one you want covered. The other options address certificate revocation status checks rather than domain matching, so they don’t fit the purpose of covering multiple subdomains.

Wildcard certificates secure many subdomains under a single parent domain by using a wildcard character in the domain field, typically in the form *.example.com. This means subdomains like shop.example.com, login.example.com, and api.example.com are covered by one certificate, simplifying management and reducing the need for separate certs for each subdomain. However, the wildcard usually covers only one level of subdomains and doesn’t automatically cover the root domain example.com unless that is included separately (often as a SAN).

A SAN certificate, on the other hand, lists multiple exact hostnames (such as sub1.example.com, sub2.example.com) but doesn’t automatically cover all subdomains under a parent—you’d have to enumerate each one you want covered. The other options address certificate revocation status checks rather than domain matching, so they don’t fit the purpose of covering multiple subdomains.