SSH key authentication lets users log into servers without the need to use their user’s passwords which increases security.

Step 1: Create a key (if you don’t already have one)

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ssh-keygen -t rsa

_{Note: for extra security, add a passphrase to your key when prompted.}

Step 2: Copy the key to your server

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cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

Step 3: Disable root login and password login for users

Modify /etc/ssh/sshd_config configuration file to include the following (if not already there):

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PermitRootLogin no
PasswordAuthentication no

Step 4: Restart your ssh service

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sudo systemctl reload sshd.service