The Zip file format is such that the files added to a Zip file are encrypted, whereas the Zip file itself is not. Therefore, any user can open a Zip file and see the list of files even when those files are encrypted. However, the user will not be able to extract or view the encrypted files unless he or she enters the correct password to decrypt them.
To hide the names of the files in your encrypted Zip file, you can double zip them. To do this:
- Zip your files without encrypting them
(Use any compression setting you choose with this step)
- Save the Zip file with a name meaningful only to you
- Close this Zip file
- Create a new Zip file, add* the first Zip file to it, and Encrypt this time
- You may want to permanently delete the first, unencrypted Zip file created in step 2 at this point (press Shift+Delete)
*Note: You cannot add one Zip file to another by using drag and drop in an open WinZip window. When you drop a Zip file into an open WinZip window, the assumption made by the program is that you want to open that Zip file. You should click the Add Files button on the Edit tab instead.
These steps will produce an encrypted Zip file which will display only the name of the first Zip file when it is opened.
If you have any questions about this information please email Technical Support.