256-bit AES is stronger than 128-bit AES, but both of them can provide significantly greater security than the standard Zip 2.0 method described below. An advantage of 128-bit AES is that it is slightly faster than 256-bit AES, that is, it takes less time to encrypt or decrypt a file.

Unfortunately, this simple compression technology lacks basic security. As such, there is a risk of compromise or misuse even when sharing files between known parties. One way to strengthen security of Zip files is by password-protecting them, in the same way you can password-protect PDF files or other documents.

In the main WinZip window, select all of the files in the WinZip file (Ctrl+A is a handy keyboard shortcut). Click Encrypt In the Tools tab . In the Encrypt dialog, enter the password in the Enter password and Re-enter password (for confirmation) fields and then click OK.

Creating an Encrypted File When you've reached the right folder that contains the file you want to encrypt, right-click on the file. Select 7-Zip and click on Add to Archive... The only details you need to enter are the Encryption Password. Enter a password of your choice, then re-enter to confirm.

One thing to keep in mind though is that if you're sharing confidential information, you'll need to encrypt the zip file before sending it via email. Email on its own does not protect your information whatsoever.

Protect and compress your PDF documents Open a PDF in Acrobat. Select Protect from the menu on the right. In the Protect banner above the document window, click Protect Using Password. Type in your password and save it in a safe location because password recovery is not available.

Fortunately, most third-party zip tools, including the free 7-zip, support AES-256. To encrypt an archive in 7-zip, once you're at the Add to Archive dialog box, enter a password and select the Encryption method AES-256. You'll find these options near the lower-right corner of the dialog box.