Mastering Linux Security and Hardening - Second Edition

Commercial certificate authorities

To make this magic work, you need to install a security certificate onto your web server. The certificate serves two purposes:

• It contains the public key that's needed to set up an asymmetric key-exchange session.

• Optionally, it can verify the identity of, or authenticate, your website. So, for example, users can theoretically be sure that they're connected to their real bank, instead of to Joe Hacker's Bank of Crooks and Criminals that's disguised as their bank.

When you shop for a certificate, you'll find quite a few vendors, which are all referred to as certificate authorities, or CAs. Most CAs, including vendors such as Thawte, Symantec, GoDaddy, and Let's Encrypt, among others, offer several different ...