How do you secure your confidential data on your PC and keep it say from would be data thieves? If you’ve got a great deal of sensitive files you probably turn to any number of 3rd party software, both free and paid. However, if you just have a couple bits of information to secure, like a few passwords, or otherwise need to secure something quickly you likely wouldn’t think to turn to the universal text file!

As shocking as it may sound, it’s actually possible to store sensitive information within a plain text file and still have the file readable through Notepad – all without any additional software. The solution leverages NTFS, the Windows file system, and it’s Alternative Data Stream (ADS). ADS are not listed in Windows Explorer and are therefor not included in the displayed file size.

Here’s how ADS works.

Open a Command Prompt. The syntax to use is notepad filename:streamname.

A dialog prompt will then request confirmation.

In the Notepad editor record any of the secret information you wish to keep safe and save the file.

Any file can contain multiple streams, as long as your stream names are kept unique.

Now that we’ve hidden our secret information away in the ADS of an every day text file – how do we retrieve it at a later day? From a command prompt the command is more < filename:streamname

At this point you should realize the key to unlocking the data is simply knowing the file that contains the ADS as well as the name of the stream! The beauty of this type of security through obscurity is your ability to continue to use the container file just like any other file. That is, changing the contents my_plain_file.txt will not affect the encoded data.

Of importance, the alternative data stream is a function of the Windows file system, specifically NTFS, so transferring the file to a different system will cause the contents of the data stream to be lost. This includes posting the file online, emailing it, or storing it on a FAT formatted thumb drive.