|WinZip creates Zip files that abide by the specifications as published in the .ZIP Application Note. Encryption is applied to files that are being zipped. This encryption is added after compression and does not affect any other associated data. Data in a Zip file is encrypted byte-for-byte.
WinZip can encrypt files while you create Zip files (.zip or .zipx) and can also add encryption to existing Zip files.
Encrypt while creating Zip files
- Click the Encrypt toggle in the Actions pane (or the Encrypt button in the Create/Share (Edit) tab
- If you have not already done so, click the Options button that now displays in the Actions pane to set your encryption level (this can also be set in the Conversion Settings drop down menu on the Settings tab)
- Add files to your new Zip file
- Enter a password when the Encrypt dialog displays
- Save the Zip file
XP users would check the Encrypt added files box in the Add dialog.
If you are creating a Zip file in a folder window using the context menu (right click), you will have the option to encrypt the files and select encryption strength if the Add dialog is displayed. If you choose to add files to an existing Zip file using Add to recently used Zip file there will be no Add dialog and therefore no opportunity to encrypt the files while they are being added. In such a case, you can encrypt files after they have been added. You have the option to click Zip and Share (WinZip Express) when you right click, if you have the WinZip Express for Explorer add-on installed. With WinZip Express you can zip, choose to encrypt, and make use of many additional options such as saving to a cloud service.
Encrypting data in an existing Zip file
In the WinZip user interface
- Open the Zip file
- Click the Encrypt toggle in the Actions pane, click Options below the toggle when it appears, and click Apply to all files in the Zip
or - Click Selected Files on the Tools tab, check the box next to Encrypt files, and click the Convert Selected Files button
- Right click on the Zip file in a folder window
- Choose WinZip
- Click Encrypt
In each case, WinZip will ask for a password and then encrypt all files currently in the Zip file. Depending on the method you use, you may or may not have the option to change the encryption strength.
If a file in the Zip file is already encrypted, it will first be decrypted and then re-encrypted using the password and encryption method you specified. WinZip will first try to decrypt the file using the current password; if the file cannot be decrypted with this password, WinZip will ask you for the correct password. If you are unable to supply the correct password, the file can be skipped, and it will remain unchanged in the Zip file. The password you entered in the Encrypt dialog box will remain active until either you delete or replace it, or you close the archive.
If you have any questions about this information please email Technical Support.
What is AES Encryption?
How strong is WinZip's encryption?
Password Policy for Encryption