|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 new Zip files (.zip or .zipx) and it can also add encryption to data in existing Zip files.
WinZip in the Default view:
WinZip in the Classic view:
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.
Another option would be to use WinZip Express for Explorer. To do this, 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 saving to a cloud service.
In the WinZip user interface:
In a Windows Explorer folder window:
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 submit a Technical Support ticket.