You should be using different key pairs on each client machine you log into. You should also be using different key pairs for each host to which you connect (an

You should be using different key pairs on each client machine you log into. You should also be using different key pairs for each host to which you connect (and using ~/.ssh/config to specify which keys are sent to which hosts.) Not only will this limit correlation as demonstrated here, but also make it much easier to revoke access via keys that may have been compromised.