Digital Certificate

A set of authentication and identification information issued by a Certificate Authority.

Digital certificates are presented in the X.509 format, and they're used to provide proof that a keypair provided by the server that has the certificate can be trusted for a specific user, host, or service.

Attributes

X.509 Version
Serial Number
Signature Algorithm
Issuer
Valid From/To
Subject
Public Key

Certificate Authorities

CAs are public servers that provide identity checking by issuing these certificates to servers.