Security

Use only passwords and use good ones - at least 9 characters long, a mixture of alphanumeric and non-alphanumeric characters and of mixed case. The password should be completely different to the password you use on any other system. NEVER copy a private key anywhere! The private key should remain in your .ssh directory on the system you generated it on and should be readable only by you. SSH key passphrases should be as secure as other passowrds. Never setup passphraseless ssh keys to allow unauthenticated login access between systems.

WARNING: Incorrectly configuring ssh keys can leave your accounts vulnerable to attack and, more importantly, can provide attackers with a trivial means to transfer their attacks to other systems and organizations.