Key-based SSH login | Passwordless SSH | Linux Administration | DevOps

Learn how to configure passwordless SSH login or key-based SSH authentication in Linux.
In the previous video, we learned how to log in to a remote host using SSH. In that video, we saw that login to a remote server using SSH required a password. But in this video, we are going to configure key-based authentication so that we will not be asked to enter the login password while doing SSh to the remote server.

You may be afraid that, if the user on the remote host doesn’t ask for a password, it’s very insecure and anyone can log in and do whatever they like on the server. That’s not true. After configuring the key-based authentication, only the host that has the private key can log in to the remote server.

While performing passwordless or key-based SSH authentication, there will be a key exchange between the remote host and the local host or your PC. We will generate the private and public keys on the local host. Then we will send the public key to the remote host. But, the private key must be kept secret because, if an attacker gets the key, he can log in to the server without a password. To sum up, key-based SSH authentication requires the exchange of keys between the source and destination hosts.

With that brief theoretical information, I hope you have known a little bit about how key-based SSH authentication actually works. Now, let’s move on and learn it practically.