I have generated private and public key pair files (id_rsa, id_rsa.pub) using ssh-keygen command in a machine A, which is a client. I have tested my connection to server in machine A and it is working fine. Now I have copy those files using cp command to a machine B (~/.ssh folder) and I can't login anymore. Once I deleted my public key file, I can successfully login into server. However, my X2goclient can't connect and prompt up multiple times the paraphrase window with and without the public key.
What is the adequate procedure to copy those keys from client to client (Machine A to Machine B)?