TElPDFPasswordSecurityHandler is a descendant of TElPDFSecurityHandler.
TElPDFPasswordSecurityHandler is a security handler that provides support for password-based document encryption. It's possible to use encryption with two passwords: author's password and document password. Correct author's password allows to edit the document completely while user's password allows only actions specified in Permissions.
To use this class in the development and distribution of your software projects, you need to purchase one of the following licenses:
PDFBlackbox OR SecureBlackbox Data Security OR SecureBlackbox Professional