If you have executable files and program which you would like to be accessed just by you , Empathy is a good solution which wraps up the porgam with your own password. Juts select the file , give the password and you are done. And yes it does backup the original exe file just in case you also forget the password.
However What made me write about this is , the software is free but postcardware i.e. You need to send this guy a post card ( not electronic ) at his address and he will send you the code which will allow you to use empathy with complete functionality.
Intresting!!! No Money all free but needs a postcard. I wonder if he is reading this may be can share in comments what was his idea of making this a postcardware. Download Empathy