Digital certificates: identity, keys and trust

A digital certificate associates a public key with identity information under an issuer’s signature. The receiving application validates it against its own trust configuration.

Validation includes the expected service identity, validity period, permitted usages and issuer chain. A valid certificate does not establish that a service is harmless or that its private key is well protected.

The guide below explains these components. The private PKI lab shows a certificate authority and client configuration.