EO.Pdf fully supports PDF encryption. It can both read and write encrypted PDF files.
>//Load inputFileName with password "1234"
//Set a new password "5678"
'Load inputFileName with password "1234"
'Set a new password "5678"
The PDF encryption API not only can be used to password protect a PDF file, but can also be used to restrict file permissions. For example, it can be used to disallow user from printing a PDF file.