Certificate Authorities (CA) are entities responsible for issuing digital certificates to verify identities on the internet. Public CAs are common for verifying the identity of websites and services provided to the general public, but private CAs are useful for closed groups and private services. With a private CA, you can issue certificates to users, servers, or individual programs within your infrastructure. In this guide, we’ll set up a private CA on a your server, and learn how to generate, sign and revoke certificates. Choose your operating system to begin.