EncryptionOwnerPassword Property

The owner password

This password is sometimes also referred to as the author’s password. This password grants full access to the document. Not only can the document be opened and read, it also allows the document's security settings, access permissions, and passwords to be changed.

If the password contains characters that are not in the Windows ANSI encoding (Windows Code Page 1252), the output document's compliance level is automatically upgraded to PDF version 1.7. This is because older PDF versions do not support Unicode passwords.