In public-key authentication, the server authenticates the user by the presence of the user's public key in the user's
$HOME/.ssh2 directory on the server. The public key ties the user ID to the user's private key stored on the client. Keys can be generated using the ssh-keygen-g3 tool.
For more information on public-key authentication, see User Authentication with Public Keys in File and Tectia Server for IBM z/OS User Manual