Multi-domain SSL

Multi-domain SSL definition

Multi-domain SSL is a SSL/TLS certificate that allows users to secure multiple domain names with a single certificate.

See also: SSL encryption, SSL stripping attack, SSL offloading, strict SSL

Examples of multi-domain SSL

Multi-domain Domain Validated (DV)

• Validation level: Low. It only verifies that the applicant has control over the specified domain names.
• Visual indicators: Standard padlock in the address bar.
• Suitable for blogs, informational websites, and other sites where trust isn't critical.

Multi-domain Organization Validated (OV)

• Validation level: Medium. It verifies domain ownership and conducts additional checks to validate the organization's identity.
• Visual indicators: Standard padlock in the address bar. Certificate details will show organization information.
• Suitable for businesses — especially e-commerce — where customers need some level of trust to use the service.

Multi-domain Extended Validation (EV)

• Validation Level: High. It conducts thorough checks on the organization, including verifying its legal, physical, and operational existence.
• Visual indicators: The visual representation varies across browsers and their versions. EV certificates used to display a green address bar and show the organization's name. However, browser updates have mainly changed this representation, often limiting the distinctive appearance.
• Suitable for high-profile websites, financial institutions, and other businesses where the highest level of security and customer trust is essential.

Wildcard SANs in Multi-domain SSL

• While not strictly a separate “type,” some multi-domain SSL certificates allow for the use of wildcard SANs. This means that not only can you specify multiple distinct domain names, but you can also use wildcards for subdomains. For example, a single certificate could secure both example.com and *.example.net.