ssh: The authenticity of host 'hostname' can't be established

Question

When i ssh to a machine, sometime i get this error warning and it prompts to say \"yes\" or \"no\". This cause some trouble when running from scripts that automatically ssh

Answer 1

The following steps are used to authenticate yourself to the host

1. Generate a ssh key. You will be asked to create a password for the key

ssh-keygen -f ~/.ssh/id_ecdsa -t ecdsa -b 521

(above uses the recommended encryption technique)

2. Copy the key over to the remote host

ssh-copy-id -i ~/.ssh/id_ecdsa user@host

N.B the user @ host will be different to you. You will need to type in the password for this server, not the keys password.

3. You can now login to the server securely and not get an error message.

ssh user@host

All source information is located here: ssh-keygen