What does the acronym SAN stand for in digital certificates?

The acronym SAN in the context of digital certificates stands for Subject Alternative Name. This is an extension to the X.509 specification that allows users to specify additional host names for a single SSL certificate. The significance of the SAN field is that it enables a digital certificate to secure multiple domain names or IP addresses, which is useful for organizations that manage various services on different domains or subdomains.

When a digital certificate includes SAN, it helps browsers and other software to validate and recognize multiple identities for a single entity. This is particularly critical for organizations looking to streamline their certificate management and reduce the costs associated with maintaining separate certificates for each domain or subdomain. The SAN feature is widely utilized in multi-domain SSL certificates and is essential for any comprehensive security architecture involving multiple online services.