|WinZip creates Zip files and abides by the published .ZIP Application Note. In Zip files, encryption is applied only to the content of files. It is performed after compression, and not to 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
WinZip ribbon interface
- Click the Encrypt button in the Create/Share (Edit) tab
- If you have not already done so, use the Conversion Settings drop down menu on the Settings tab to set your encryption level
- Create a new Zip file
- Enter a password when the Encrypt dialog displays
- Save the Zip file
- Open WinZip and click Add
- In the Add dialog, check the Encrypt added files box
- When the Encrypt dialog displays specify an Encryption method
- Enter a password and click OK
- Save the Zip file
If you are creating a Zip file in a folder window using the context menu (right click), you will have an option to encrypt the files 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. If you have the free WinZip Express for Explorer add-on installed, you also have the option to click Zip and Share (WinZip Express) when you right click. With WinZip Express you can zip, choose to encrypt, and make use of many additional options such as conversions and saving to a cloud service.
Encrypting data in an existing Zip file
- Open the Zip file
- WinZip ribbon interface - Click Convert Selected Files on the Tools tab, check the box next to Encrypt files, and click OK
Legacy menus/toolbar - Click the Encrypt button or click Encrypt on the Actions menu
- Right click on the Zip file in a folder window
- Choose WinZip
- Click Encrypt
In each case, WinZip will ask for a password (and encryption method if you are using the Classic interface) and then encrypt all files currently in the Zip file.
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, please email Technical Support.
What is AES Encryption?
How strong is WinZip's encryption?
Password Policy for Encryption