Answered
When setting up a security password for a document to determine what will be allowed to do to a document once you send it out by email, I noticed that you can stop the recipient from printing, copying, etc., but they can email the document to someone else. Is there a way to stop them from emailing the document as well? In other words make sure that they can view it, but they cannot send it to someone else to view.
The short answer is no. If you don't want unauthorized eyes looking at the document there are a couple of other steps you could take. The easiest thing is to use a Document Open password along with the Permissions password. Of course, if you can't trust the document recipient not to forward the document along, you probably also wouldn't trust them not to share the Document Open password.
A more secure form of encryption is Certificate Security. That's where you encrypt that the file using the recipients public-key certificates and they use their corresponding private keys to open the file. That way you control who has access to the file. People are less likely to share their private keys then they are a password.
In the end, it's very hard to prevent data from being compromised if someone really wants to do it. If they can get the file open they could take screen shots of the pages and send those out, or even take a picture of the screen and e-mail the image file.
The most secure way of encrypting a PDF file is to use the LiveCycle Rights Management Server. That way you can track who opens the file and what they do with it. Also, you can add dynamic watermarks to a file so if the take a screen shot you it would identify the culprit.
Steve
Steven Madwin
Software QA Engineer
Adobe Systems Incorporated
345 Park Avenue, MS-W15
San Jose, CA 95110-2704 USA
408.536.4343 p, 408.537.4053 f
Steven [dot] Madwin [at] adobe [dot] com