How to access local server without password

We will save time for access to easily. Also you can access to another co Worker without giving you the password.

When you want to remove the access to user. You don't need to change the login password of the server.
You only to have to remove the string key public from user that file is called authorized_keys.

Step 1: Create Your ssh key like client

You must be the next command: This generated your keys (a private key and a public key)
this files will be created into the folder: /home/user/.ssh/

ssh-keygen

Generating public/private rsa key pair.
Enter file in which to save the key (/home/user/.ssh/id_rsa): 
Created directory '/home/user/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/user/.ssh/id_rsa.
Your public key has been saved in /home/user/.ssh/id_rsa.pub.
The key fingerprint is:
8c:2a:ed:82:98:6d:12:0a:3a:ba:b2:1c:c0:25:be:5b

Step 2: Add the public key in Server

sudo apt install openssh-server

nmap 192.168.1.62

ssh-copy-id -i ~/.ssh/id_rsa.pub pi@raspberrypi

pi@raspberrypi's password: ********
Now try logging into the machine, with "ssh 'username@remoteserver'", and check in:
~/.ssh/authorized_keys
to make sure we haven't added extra keys that you weren't expecting.

ssh pi@raspberrypi

Reference: www.shellhacks.com