PDF Owner Guard is a reliable digital rights manager (DRM) and data protection system which not only lock your protected documents to specific computer(s) using the computer ID or user account name etc, but also control and apply limitations for viewers using a user side DRM component called License Manager. This minimizes your users DRM hassles by letting them access your secure PDF files offline.
The License Manager is a tiny module which lets users add owner-generated licenses and access protected files. And also, the users do not need to run any additional application to access them.
It supports a wide range of limitations for data users including working time, expiry date, and print and save functions, clipboard copying, screen-capturing, etc. Moreover it provides more security features than Adobe’s DRM method offered and also the personal edition is completely free. You can download it from program's homepage.