Configure SSH server to login with Key-Pair Authentication. Create a private key for client and a public key for server to do it.
[1] Create Key-Pair for each user, so login with a common user on SSH Server Host and work like follows.

# create key pair
[cent@localhost ~]$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/cent/.ssh/id_rsa):   # Enter if keep default
Created directory '/home/cent/.ssh'.
Enter passphrase (empty for no passphrase):   # set passphrase (set no passphrase to Enter with empty)
Enter same passphrase again:
Your identification has been saved in /home/cent/.ssh/id_rsa.
Your public key has been saved in /home/cent/.ssh/id_rsa.pub.
The key fingerprint is:
38:f1:b4:6d:d3:0e:59:c8:fa:1d:1d:48:86:f0:fe:74 cent@localhost.local
The key's randomart image is:

[cent@localhost ~]$ mv ~/.ssh/id_rsa.pub ~/.ssh/authorized_keys

[2] Transfer the secret key created on the Server to a Client, then it’s possbile to login with keys authentication.

[root@node1 ~]$ mkdir ~/.ssh
[root@node1 ~]$ chmod 700 ~/.ssh
# copy the secret key to local ssh directory
[root@node1 ~]$ scp cent@10.0.0.30:/home/cent/.ssh/id_rsa ~/.ssh/
cent@10.0.0.30's password:
id_rsa
[root@node1 ~]$ ssh -i ~/.ssh/id_rsa cent@10.0.0.30
Enter passphrase for key '/home/cent/.ssh/id_rsa':   # passphrase
Last login: Wed Jul 30 21:37:19 2014 from node1.local
[cent@localhost ~]$   # just logined

[3] If you set [PasswordAuthentication no], it’s more secure.

[root@locahost ~]# vi /etc/ssh/sshd_config
# line 65: turn to [no]
PasswordAuthentication no
# line 69: make sure the value is [no]
ChallengeResponseAuthentication no
# line 96: make sure the value is [yes]
UsePAM yes
[root@localhost ~]# systemctl restart sshd

It’s the example to login to SSH server from Windows Client. It uses Putty on here.
Transfer a secret key to Windows Client first.
[4] Download [Puttygen.exe] from Putty Site and save it under the Putty directory. Next execute it and click [Load] button.

[5] Specify the secret key which you downloaded, then passphrase is required like follows, answer it.

[6] Click [Save private key] button to save it under a folder you like with any file name you like.

[7] Start Putty and open [Connection] – [SSH] – [Auth] on the left menu, then select the [private_key] which was just saved above.

[8] Back to the [Session] on the left menu and connect to the SSH server.

[9] The passphrase is required to login, then answer it. If it’s correct, it’s possible to login normally like follows.