You want to use Linux and OpenSSH to automate your tasks. Therefore you need an automatic login from host A / user a to Host B / user b. You don't want to enter any passwords, because you want to call ssh from a within a shell script. First log in on A as user a and generate a pair of authentication keys. Do not enter a passphrase: [email protected]:~> ssh-keygen -t rsa Generating public/private rsa key pair.