I can't count how many times I have typed my ssh key passphrase whenever my ssh connection times out, it is so annoying and repetitive.
Well, thanks to the putty pageant, you can do that seamlessly. The pageant is an SSH authentication agent. It holds your private keys in memory, already decoded so that you can use them often without needing to type a passphrase.
The good thing about this agent is that you can add as many keys as possible, and when you start PuTTY and open an SSH session to a site that accepts your key. PuTTY will notice that Pageant is running, retrieve the key automatically from Pageant, and use it to authenticate.
You would be able to open as many PuTTY sessions as you like without having to type your passphrase again.
To get started, open the pageant program in your putty program directory.
When you run Pageant, it will put an icon of a computer wearing a hat into the System tray:
This won't do anything, so, you would want to load a private key into it.
Right-click the pageant icon, and select the Add key button. Find your private key file in this dialog, and press ‘Open’.
Pageant will now load the private key. If the key is protected by a passphrase, Pageant will ask you to type the passphrase. When the key has been loaded, it will appear in the list in the Pageant window.
To view the key you've added, right-click the pageant icon, and select view:
You can add more key if you want.
Now start PuTTY and open an SSH session to a site or server that accepts your key.
The key would be automatically retrieved from Pageant, and authenticate. You can now open as many PuTTY sessions as you like without having to type your password again.