Which certificate type requires more rigorous checks on the subject's legal identity and control over the domain or software the certificate authority (CA) signs?

The Extended Validation (EV) certificate type requires more rigorous checks on an individual’s or organization’s legal identity and their control over the domain or software for which the certificate authority (CA) signs. This stringent verification process is designed to provide a higher level of trust to users by ensuring that the entity requesting the certificate has undergone thorough verification procedures.

To obtain an EV certificate, the CA must validate the applicant’s legal existence, operational existence, and exclusive control of the domain. This process involves extensive documentation and validation steps, which increase the assurance level for users when they see the certificate in their browser, often denoted by a green address bar or the name of the organization.

By contrast, other certificate types, such as Domain Validation (DV) certificates, require much less verification, primarily confirming that the applicant has control over the domain itself without thorough checks on the entity's legal identity. This difference in validation levels underscores why EV certificates are considered to offer enhanced security and trustworthiness, making them essential for websites that handle sensitive transactions or information.