How to lock a file completely from being read

The best way would be to write a KMD which hooks NtCreateFile, and then check for the filename, and if it's one of your files, return a failure code (or hook some of the directory listing API's to remove the name from the list).

There are also programs for hiding files and folders, most use the KMD method. So you can just download one of those programs and try that. They hide a folder or file from even windows explorer, so they should work fine. Just Google it.

-Lunar