Domain validation is the check a certificate authority uses to confirm that the requester controls a domain name before issuing a TLS certificate. Common validation methods include DNS records, HTTP responses, or email-based challenges. The goal is to prove authority over the name, not to inspect the website’s content or verify the organization behind it.
In cyber security, domain validation matters because a valid certificate can make a fake site look trustworthy in browsers and security tools. Attackers try to abuse this process by taking over DNS, intercepting validation requests, or exploiting weak administrative controls so they can obtain certificates for domains they do not own. Defenders monitor certificate transparency logs, lock down DNS and registrar access, and alert on unexpected validation activity. If the validation step is protected, unauthorized certificate issuance becomes much harder.