Below is an article aimed at PHP developers who want to automatically upload a PDF to VeryPDF’s online DRM/enciphering service using PHP + cURL. It explains what the example script does, how to run it, and what every POST parameter
How to Secure and Lock PDF Files to IDE, SCSI, or USB Hard Drives Using WMIC Serial Numbers and VeryPDF DRM Protection
If you want to protect your PDF files and ensure they can only be opened on a specific hard drive or USB drive, you can use hardware-based DRM. One of the most reliable ways to achieve this is by obtaining