I have Acrobat X and am using a watched folder and Distiller to generate encrypted .pdf documents.
Distiller is set to 128 bit encryption and I don't see any way to change that.
The help button on the Distiller security settings dialog links to a help page about Acrobat security instead of Distiller ( I filed a bug about that already).
Thanks in advance for any help.
Acrobat Distiller uses only 128 bit encryption.
The user will probably have to open each file and set the security in Acrobat after Distiller has made them.
Beware of 256 bit encryption, it puts severe limits on the software people can use to read the files.