Encryption

You can encrypt the PDF output to protect the generated PDF documents from unauthorized access. Encryption only applies to the contents of the document. It does not apply to other object types that are used to convey information about the structure of the document.

The filter that controls access to the contents of the encrypted document is the security handler. The security handlers available in PDF are Standard Security Handler revision 2 and Standard Security Handler revision 3.

Standard Security Handler revision 2

Algorithm	RC4 with 40-bit keys.
Passwords	User and owner passwords can be specified.

Standard Security Handler revision 3

Restrictions	Acrobat version 4.05 and PDF version 1.4 or higher.
Algorithm	RC4 with 128-bit keys.
Passwords	User and owner passwords can be specified.