7-Zip is a file compression and encryption format available for PC and Mac. It can be used to create encrypted file archives with a .7z file extension.
(Mac instructions also available)
Download the 7-Zip .exe program at http://www.7-zip.org/.
7-Zip creates a compressed file that contains one or more files or folders. If you want to include several files in your 7-Zip archive, you will first need to put them all in one folder. If you have questions or require assistance, please contact the ITS Help Desk at (850) 474-2075 or email@example.com.
Right-click the file you want to encrypt and select 7-Zip, then click Add to archive....
Type a password, then reenter the password. If you do not enter a password, your file will be compressed, but it will not be encrypted. For maximum security, select a long password containing letters and numbers. Then click OK. The encrypted file is created and saved in the same location as the .7z file.
If you will be sharing this file with someone, you must provide them with the password, preferably in-person or over the phone. Never send the password in the same email as the attached file.
Right click the encrypted file and select 7-Zip, then click on either Open archive (to view the contents - if it contains more than one file) or Extract files... (to unencrypt all of the contents).
Enter the password that was used to encrypt the file, then click OK.