The value of an SSL is protected by the strength of a standard two-point validation process:
– Step 1: Verify that the applicant owns, or has legal right to use, the domain name featured in the application.
– Step 2: Verify that the applicant is a legitimate and legally accountable entity.
The compromise of either step endangers the message of trust and legitimacy provided to the end consumer. This validation step relies on the use of Domain Name Registrar details to validate ownership of a domain name and then a challenge email is sent to the listed administrator of the domain name. If the challenge is met with a successful reply, the Certificate will be issued.
Content retrieved from: https://support.appliedi.net/kb/a742/what-is-ssl-validation.aspx.