Public-key authentication is is based on the use of digital signatures. Each users have to create a pair of keys. ie public key and private key. Private key is owned by user and the public key is given to the server. When the user tries to authenticate, server check for the matching public key and sends a challenge to the user. Private key is used to authenticate the user, so never provide your private keys to others. If anyone got your private key, they can login to the server as you. So keep your private key file in a secure place and make sure that no one else has access to it.

Secure Shell (SSH) public key authentication is used for clients to acess servers without using passwords.

Steps to configure public key.

OpenSSH is the SSH software installed on the client system. The ssh -V will show the openssh details in the server. (more…)