If all you want is to encrypt a text file, then using a general file encryption tool may have few drawbacks. One is that, a lot of those tools aren’t portable so in order for you to view the text on another computer, then you’ll have to have the encrypting tool installed.
If you use a tool like ‘CTI Encryption’ on the other hand, not only it’ll encrypt/decrypt the text file but because it has a simple text viewer embedded, you can also view (and copy) the text file as soon as it decrypts the file.
It supports using multiple ‘keys’ (passwords or pass phrase in other words. Including the ability to use your CPU or HDD’s device ID/Serial-Number as a key file), doesn’t require any installation so you can put it into a USB drive and is reasonably portable as well.
The reason I said ‘reasonably’ was because, older versions of Windows such XP need to have the ‘.NET Framework 2.0’ installed first (should run natively on Windows Vista and 7).
Though most users wouldn’t need it, but it also lets you create ‘hash values’ using text phrases too.
Using it is pretty easy. First copy the text content that you want to be encrypted, then click on the ‘Paste’ button on CTI’s main window , then enter one or more passwords, press the ‘Encrypt’ button, and you’ll see the encrypted text output.
Then click on the ‘Save’ button and it’ll save the encrypted text output into a text file and you can use the ‘Open’ button for decrypting it later. You can change the font and enable ‘word wrap’, show hide the key files and change a few of ‘one way encryption’ related settings as well.
It’s completely free, comes with Apache License (open source), if interested, please visit this page and get it. Good luck.