# Certificates & public keys

## Introduction

In cryptography, a public key certificate, also known as a digital certificate or identity certificate, is an electronic document used to prove the validity of a public key.

The certificate includes information about the key, information about the identity of its owner (called the subject), and the digital signature of an entity that has verified the certificate's contents (called the issuer).

If the signature is valid, and the software examining the certificate trusts the issuer, then it can use that key to communicate securely with the certificate's subject.

For more information, see Wikipedia's articles on [X.509](https://en.m.wikipedia.org/wiki/X.509) and [Public key certificates](https://en.m.wikipedia.org/wiki/Public_key_certificate).

To be notified of any future updates to any of our certificates and/or keys, please sign up for automated notifications via our Platform updates page.

[!ref Platform updates](../platform-updates.md)