Printing and Signing PDF Security Questions

Question

Hi,
I noticed one of the PDF security features for Acrobat 8.0 is to set the printing permissions between "None", "150 DPI", and "High Resolution". However, when I print between two PDF's with 150 DPI and max resolution, I honestly can barely notice the difference between the two (the 150 DPI is "slightly" worst, i.e. letters are slightly more jaggedly). I was wondering is this normal, as I was hoping the lower setting would make the printout hard to read, not just a "quick-print" (I used a Laser Printer with 1200 DPI). I don't mean to make a big deal out of it, but I personally do not think this a very useful feature from a security standpoint.
Secondly, I'm having trouble creating signable PDF's. I basically want the file to only allow a user to sign, and nothing else, so I set the "Changes allowed" to just "filling in forms and signing existing signature fields". But doesn't seem to work, because instead I have to set it to allow "any except extracting page". Only then can I sign the PDF, but then this also allows it to be changed (which I don't want). Is there something wrong with what I'm doing? Any help is appreciated!

Answer 1

It's a very common question, and as Michael says there's not a lot you can do. Even doing the imposition yourself is unlikely to help, as most commercial raster image processors (RIPs - the software which turns your document with its fonts, graphics etc into the pattern of dots needed to physically generate the image on the printing drum) need unencrypted files.
If the print shop has an ad-hoc workflow which supports encryption (such as printing direct from Acrobat in the way desktop users do), there are plugins for Acrobat to handle the page imposition; but it's not something native to the application and the printer will have to give you very precise directions as to what layout to create. Many print shops won't entertain that idea unless there's an overriding commercial reason, as it's too much hassle for them to deal with errors in the client plates. Worth asking, but I doubt they'll agree to it.
Given the need to send unsecured files to an external contractor for printing, your "protection" is in the form of the contract, not digital encryption. The former can be settled in court if they break the terms, the latter can be bypassed in ten seconds and you'll probably never know. If the files are truly too sensitive to send to anyone, it's time to get yourself a laser printer - these days the machines many local print shops rely on are in essence a color photocopier, and you can rent them for about the same price.