You can encrypt files when you add them to an archive or when they are in an existing archive. PK Protect encrypts the files using your current settings (on the ZIP or OpenPGP page of Security options) for encryption method, whether to encrypt file names, and so on.
To encrypt (or re-encrypt) files that are in an existing archive, use the Encrypt button on the Actions group. The Encrypt files option does not need to be set to use the Encrypt command. (The option turns on encryption for the next time you add files; the command immediately encrypts archived files.)
Note: The Encrypt files option must be turned on to encrypt file names. File name encryption is added only if both Encrypt files and Encrypt file names are checked on the ZIP page of Security options. You cannot encrypt file names with OpenPGP.
To remove file name encryption from a file-name-encrypted archive, clear Encrypt file names and choose the Encrypt command.
If some files that you select in an archive are encrypted already when you choose the Encrypt command, PK Protect asks if you want to replace the current encryption. If you do, PK Protect decrypts the files and then re-encrypts them using your current settings.
PK Protect prompts you for any passphrases or private keys needed to decrypt. If PK Protect cannot decrypt some files (because you forgot the passphrase, for example), they keep their original encryption.
To encrypt files that are already in the current archive:
1. In the main window, select particular files to encrypt, or deselect all files (click in an empty area) if you want to encrypt all of them.
If no files are selected, all will be encrypted. Selecting zero files has the same effect as selecting all files.
2. Click Encrypt on the Actions group.
Depending on your settings, PK Protect prompts you to define a passphrase and/or keys to use to encrypt the files.
If some files are encrypted already, PK Protect lets you choose whether to replace their encryption.
3. Save the archive to confirm the change.