If you want to know what SSH in general is go to the home of Ssh and follow the links from there. AmigaSSH is based on version 1.2.26 of ssh and version 3.12 of napsaterm. I have integrated parts of ssh into napsaterm. The current version has been tested with AmiTCP V4 and Miami V3 with the standard socket.library emulation that is out there somewhere. I planned to do a gmp.library as well, and I've made all needed files but the testprogram doesn't work.
Shared libraries are really nice since several binaries can share the same code.
Download The third release of AmigaSSH is now available. Hopefully I have remembered to include everything needed to compile. I have also verified that ssh-keygen works. If you want to use z.library from your own programs you probably want the original archive too since it contains some more documentation.