7-Zip is open source software used to compress or zip files secured with encryption.
When you send or transfer files that contain Personal Identifiable Information (PII) or other confidential and sensitive data the files must be encrypted to ensure they are protected from unauthroized disclosure.
For Mac OS instructions please visit: http://osxdaily.com/2012/01/07/set-zip-password-mac-os-x/
Z-Zip, like WinZip, creates a container called an archive that holds the files to be protected. That archive can be encrypted and protected with a password. 7-Zip is free software that can create Zip files that can be opened with WinZip or other similar programs.
Once the software is installed please follow these steps to encrypt a file or folder.
Step 1: Right click on the file / folder to be encrypted.
Step 2: Select “7-Zip” then “Add to archive…”
Step 3: In the Add to Archive window change the name of the archive you wish to create.
Step 4: Change the Archive format to “Zip”.
Step 5: Change the Encryption Method to “AES-256″.
There is a trade-off between using AES-256 and ZipCrypto. AES-256 is proven much more secure than ZipCrypto, but if you select AES-256 the recipient of the zip file may have to install 7-zip or another zip program to read the file contents. Selecting ZipCrypto may allow users to open the zip file in Windows without a zip program, but it does not provide adequate protection against attackers with modern cracking tools.
It is strongly recommended to use AES-256 to protect sensitive and confidential data.
Step 6: Enter a Password. Use a strong password with at least 8 characters and containing upper and lower letters and a minimum of one number.
Step 7: Select “Ok” to create the encrypted archive file. The new archive file will be located in the same folder as the original.
Best security practices recommend that you do not email the password with the Zip file as it could be intercepted in transit. It is better to call the recipient of the Zip file and convey the password over the phone.