How To Compress and Password Protect Files

Instruction on how to compress and encrypt files and directories allowing backup/restore on the network, or transfer data to/from Windows based PCs and Linux based PCs.

Files that are saved on the network, or are sent as email attachments can be compressed, so that it takes less time to send, and less space to store. Files sent across the network, or sent as email, should be encrypted for security purposes.

7-zip is a free program that runs under Microsoft Windows and compresses and encrypts files. It can be downloaded from http://www.7-zip.org. It can compress files or directories to a single file. It can be used from a graphic interface or from a dos window. I recommend using the graphic interface.

There is a linux version available, called 7za which can only be run from the terminal. Ubuntu based systems can install 7za by typing the following from the terminal: apt-get install 7za. Other linux distributions can get it from the repositories. Note: tar.gz files created by linux can be decompressed on a PC running Windows using 7-zip.

To compress files or directories, highlight them and then right click the mouse; Put your mouse cursor over 7-zip. The following menu will appear:

• Add to archive...

• Compress and email...

• Add to “Documents.7z”

• Compress to “Documents.7z” and email

• Add to “Documents.zip”

• Compress to “Documents.zip” and email

To generate a new archive file (.7z), click on “Add to archive”, change the suggested name (in the box below the word “Archive:”; Under Encryption, enter a password and re-enter password (or leave blank for no encryption); Click OK.

For ease of use, you may associate the “.7z” file type with the 7-zip file manager.

To extract files in an archived file, use the 7-zip file manager. Either bring up the 7-zip file manager, and double click on the archived file, or double click the .7z file to be decompressed. Either way, the file names of the compressed files will be displayed. To extract the files, click on “extract”. A screen will appear, and you can accept the “copy to” directory – or change it. Then click on “OK”. If the 7-zip file was password protected, you will be asked to input the password. For each file that already exists in the destination directory, a screen will appear asking:

Would you like to replace the existing file: Yes, Yes to all, No, No to all, auto-rename, Cancel

Select the appropriate choice.