When you create a new file and type some data, one unnamed default stream is created to store all data written to the file. Since NTFS file system in Windows 2000 or above has supported Alternate Data Streams, so you are allowed to create additional streams for text file. All data stored in the addition streams will be hidden and none of us will be able to read the data when opening the file. This may be useful when you would like to hide some sensitive info from being read by others when sharing the file to public.

To create hidden data in the text file, follow below steps:

1) Open command prompt, you may change to any directory as you like to create the text file.
2) Type notepad MyFile.txt:StoreHiddenData then press enter. MyFile.txt is the text file you are going to create whereas StoreHiddenData is the alternate stream name.
3) A message will be pop up “Cannot find the C:\MyFile.txt:StoreHiddenData.txt file”. Do you want to create a new file?”, click OK button to proceed create the new file.
4) A notepad will be pop up. Type any data that you want to be hidden from others. Save the file and you are now successfully creating hidden data for this file.

The hidden data you have created will not contribute to the total file size. Just open Explorer and look for this file, you will observe that the file size is still zero. Now you can go ahead to type some data and saved it as usual. Good thing is, it will not affect the hidden data that you have saved earlier. On top of that, you can display or delete all the hidden data you have saved previously. However, you must download and install Streams application before you can do so. To delete hidden data, go to command prompt and type more < MyFile.txt:StoreHiddenData.txt. If you want to delete all hidden data , the syntax is streams.exe –d MyFile.txt.