Transport Layer Security, or TLS, makes ecommerce and online banking possible. It protects your passwords and your privacy. Let's Encrypt transformed TLS from an expensive tool to a free one. TLS understanding and debugging is an essential sysadmin skill you must have. TLS Mastery takes you through: - How TLS works - What TLS provides, and what it doesn't - Wrapping unencrypted connections inside TLS - Assessing TLS configurations - The Automated Certificate Management Environment (ACME) protocol - Using Let's Encrypt to automatically maintain TLS certificates - Online Certificate Status Protocol - Certificate Revocation - CAA, HSTS, and Certificate Transparency - Why you shouldn't run your own CA, and how to do it anyway - and more! Stop wandering blindly around TLS. Master the protocol with TLS Mastery !.