Certificate Validation Levels and Their Significance

Domain Validated (DV) certificates represent the most basic validation level, verifying only that the certificate applicant controls the domain. This validation typically occurs through automated methods: email verification to predetermined addresses, DNS record verification, or HTTP file upload verification. The automated nature enables rapid issuance, often within minutes, and low costs, including free options from providers like Let's Encrypt. DV certificates suit websites primarily needing encryption without extensive identity verification.

Organization Validated (OV) certificates require more extensive verification, including confirmation of the organization's legal existence, operational status, and physical address. Certificate Authorities verify this information through government databases, third-party business directories, and direct contact with the organization. This additional validation provides users with more confidence about the website operator's identity, as certificate details display verified organization information. The manual verification process typically takes several business days.

Extended Validation (EV) certificates represent the highest validation level, requiring the most rigorous verification process. Beyond OV requirements, EV validation includes verification of the organization's operational existence, physical address confirmation, telephone number verification, and confirmation that the certificate applicant has authorization to request certificates for the organization. This extensive process can take weeks but provides the highest level of identity assurance, historically triggering special browser indicators like green address bars.

Wildcard and multi-domain certificates address specific deployment scenarios. Wildcard certificates secure a domain and all its subdomains with a single certificate, simplifying management for sites with numerous subdomains. Multi-domain certificates, using the Subject Alternative Name field, can secure multiple unrelated domains with one certificate. These certificate types provide operational flexibility while maintaining security, though they require careful key management due to their broader scope.