How to encrypt files into ZIP format using 7-Zip

Sometimes we are asked to send personally identifiable information via email, and the best way to do this is using an encrypted ZIP file.  The rough outline of how this should work is to:

  1. Compress the file(s) to ZIP format and encrypt using a strong password
  2. Send the encrypted ZIP file via email
  3. In a separate email, send the password for the encrypted file

If 7-Zip is not installed on your computer, you’ll need to get your System Administrator to install it first.

Encrypting and Emailing Files

  1. Pick a strong password while making sure to follow the recipient’s password requirements.  You can use the tool at to generate a strong random password that will resist most password attacks.
  2. Right click on the file or folder that you wish to encrypt.
  3. Select “7-Zip” and then “Add to archive…”
  4. On the next screen, (1) select the ZIP archive format, (2) select the AES-256 encryption method, and (3) enter your password twice.  Everything else can stay the same.
  5. Using your normal email tools, attach the resulting file to an email and send it.
  6. In a separate email, send your password.  Never send your password and encrypted file in the same email.