Certificate (Digital Certificate)

A digital certificate is an electronic document that verifies the identity of a server or entity and contains its public key.

What is a Digital Certificate?

A digital certificate is an electronic document that uses a digital signature to bind a public key with an identity. Issued by Certificate Authorities (CAs), certificates enable trust in secure communications.

Certificate Contents

Subject (identity), Public key, Issuer (CA), Validity period, Signature algorithm, and extensions.

Certificate Types

DV (Domain Validation): Verifies domain control
OV (Organization Validation): Verifies organization
EV (Extended Validation): Rigorous verification
Wildcard: Covers all subdomains
Multi-domain (SAN): Multiple domains in one cert

Common Misconceptions

"EV certificates are more secure" - Same encryption as DV
"Free certificates are inferior" - Encryption is identical
"Certificates expire for security" - Key rotation best practice