Key Based SSH Authentication on a Linux Host using Putty

In order to be more secure, I have decided to use a key instead of a password authentication. I'm using putty to connect to my linux server. I have used the following steps in order to configure it:

• Generate a public and private key with PuTTYgen (click on Generate):

The key is generated by mouving randomly the mouse.

• Save the public and private key.
• The next step is to add the public key on the server:

mkdir ~/.ssh
chmod 700 ~/.ssh

• Paste the public key to the following file:

vim ~/.ssh/authorized_keys
chmod 600 ~/.ssh/authorized_keys

• Configure the putty session:
• Create a new session and save it:

• Select data and configure 'Auto-login' (usersame used by the created key):

• Configure the path to the private key:

After this, if you open the session, you will be directly prompted to the linux host.

Multi Instances with PuttyCM

By default you can just start one puttyCM instance. For example if several users want to use a puttyCM on  server via RDP it's impossible by default. To open several session you need to modify a key register on windows. Below this key:


HKEY_CURRENT_USER\Software\ACS\PuTTY Connection Manager\
AllowMultipleInstances REG_DWORD 1