Install Notepad++ and NppCrypt plug-in
Step 1: Download and install Notepad++.
Step 2: Launch the plug-in manager by going to Plugins > Plugin Manager > Show Plugin Manager.
Step 3: Select NppCrypt from the plug-in list, then click the Install button. Allow Notepad++ to restart after the NppCrypt finishes installing.
Encrypt text
Step 1: To encrypt selected text, select the text you want to encrypt, then go to Plugins > NppCrypt > Encrypt.
Step 2: Select the cipher you want to use, then type in a password.
To encrypt the entire file, just go to NppCrypt without selecting any text and choose Encrypt. To decrypt text, go back to NppCrypt and choose the Decrypt option.
This is what an encrypted text file will look like.
(Credit: Screenshot by Ed Rhee/CNET)
That's it. Now you can encrypt select data in a text file or the entire file with ease, using Notepad++ and NppCrypt.