PGP key generation in SAP PI730

Hello Team

We need to PGP encryption in PI 730 SP00. we are going to use sftp adapter for communication.

Can some one guide me how to generate keys for this. I have gone thro below :

http://wiki.sdn.sap.com/wiki/display/XI/Generating+ASCII+Armored+PGP+Key+Pairs?focusedCommentId=341541929&#comment-341541929

I have below doubts :

We need to setup this PGP in our SAP PI 730 system.  What is difference between Generating Key Pairs and Generate ASCII Armored Keys from GPG Keys?

Do we need to login to server where we have installed on PI and generate key with Gpg4win?

What if we have HA PI 730 system , Do we need to generate on both the nodes of HA system?

Thanks

Atul