This IBM Support web page is where you can start for more information about IBM i OpenSSH and OpenSSL.
This IBM Support document reviews IBM i NetServer Best Practices.
This IBM Support document describes how to get started with the IBM i Authority Collection function.
This IBM Support document reviews how the IBM i Administration Runtime Expert provides an interface where you can compare end point IBM i systems to a central system to see the PTFs are missing. You then have the option to send, load and apply the missing PTFs to the end point systems.
This iBM Support web page describes IBM i system tasks and what they are used for.