This article will overview PDF copy protection and the available options. A couple of things worth mentioning before getting into the details:
- Encryption is different than copy protection. Encryption is a technology solution where the PDF owner assigns a password to the document and after the user enters that password the user can do anything they want with the file. Print, share, screen capture, etc. The idea for encryption is the document being unattainable until a password is entered.
- Copy protection does not use a password and anyone can see the file. However; the file cannot be copied, printed, shared or screen captured. The idea behind copy protection is the PDF being viewed by anyone, but nothing can be done with the file. When people are searching for PDF copy protection, this is the solution most likely sought after.
PDF or Portable Document Format is an open standard. What this means is the document format was designed to be used in just about any document reader program. The goal for the PDF specification was to make the format as universal as possible. For this reason, it is a bit more difficult than one would think to copy protect a PDF file.
Windows comes pre-installed with Adobe Reader. In addition, Windows has embedded Adobe API code to read PDF files. Even if Adobe Reader was not installed on your computer, or uninstalled, the underlying code is still there to open a PDF. In additional to Adobe Reader (#1 PDF reader in the market) there are dozens of additional PDF reader programs. Again, the goal for all these readers is to open and read a portable document file.
Adobe copy protection solutions are very well known for being cracked. If you Google “Adobe copy protection crack” you will find pages of ways the Adobe security features are compromised. Here and here are two examples of Google search results with web pages dedicated to hacking.
The fundamental problem with copy protection are the lack of controls when viewing a PDF. Meaning a PDF content owner (you) does not have the control over Adobe Reader, or other programs, to stop the user (your client/customer/student) from printing, screen grabbing, sharing and saving.
The idea behind a PDF copy protection solution is a framework where the PDF can be opened and viewed, while you (the content owner) maintains control of the document.
Of course Adobe Reader, FoxIt Reader and others, will not provide the tools to block a user from printing or saving from within their program. In contrast, we need a “reader” or “viewer” with controls to block those functions.
With this in mind, it is difficult to provide a reader with these security functions. Most users who receive a PDF do not want to download and install another program just to read a PDF file. The ease and beauty of a PDF gets lost in that process. No longer is the PDF a portable document format. In addition, a software program that can be downloaded to view a PDF can also be downloaded by a hacker to be reverse engineered. There needs to be something more than just a secure reader/viewer to control the PDF.
The most secure way to copy protect a PDF file is to associate it with something physical. There are some software (only) solutions, but those are not as secure as a solution with something physical.
The following article will explain how to check your USB flash drive for if it’s bootable. There is no software needed, no download, just a couple of simple commands in your Windows 10 operating system.
A master boot record (MBR) is a special type of boot sector at the very beginning of a partition storage device like a fixed disk (hard drive) or removable drive (USB thumb drive). The MBR contains executable code to function as a loader for the installed operating system. This loader turns over the functions of the hardware (mother board bios) and passes that loading responsibility off to the operating system (Windows).
This is how you check if your USB is bootable, or not:
First, please have only the one USB stick connected which you want to check if it’s bootable. It’s not required to do this, but will my the instructions below a bit easier to follow, that’s all.
Using the Windows search function copy and paste this into the search field and click Enter
The screen shot below will pop up after you click Enter. Using the image as a reference, select “Disk Management” under the “Storage” folder“. In the middle of the dialogue box you will see the drive letter associated with your USB flash drive. In the middle of the box you will probably see the USB listed two different times. The top portion of the box, the USB will be listed along with other devices, like your hard drive and optical drive. The bottom portion of the box, the USB will be shown as “Removable“
Once you’ve determined which drive letter is your USB drive, you may Right Click on the drive letter and select Properties.
A Properties dialogue box appears giving you the option to select any one of the devices show in the previous window (the Disk Management window). From this dialogue box, click the Hardware tab and select the “Mass Storage USB Device” by a single click. Then click the Properties button at the bottom.
The last dialogue box are the Properties of your specific flash drive.
Click the Volumes tab at the top, you then must click “Populate” to get the device information. . The “Partition Style” will read either Master Boot Record (MBR) or the field will be empty.
If the above information isn’t detailed enough for the information you are looking for, the next step is to use a hex editor and check if the boot strap code is actually in the Master Boot Record. This is a bit more detail and the guys at Hakzone did a really good job of summarizing how this would be done using a hex editor program.
The lifespan of a USB flash drive relates to three factors. In general terms, a flash drive will last much longer than you think and here are some details to help you understand the answer.
The three factors related to the life span of a USB flash drive are:
- How the drive is made
- Wear leveling technology
- How the drive is treated
Flash drives are a commodity product and (generally) driven by lowest price. With that in mind there are plenty of shortcuts a manufacturer can use to save time and money. What is important to understand, is knowing the quality of product you are going to use.
How the drive is made
A flash drive is made up of five primary components: The PCB (printed circuit board) the flash memory, the USB controller, the components and the soldering which holds everything together.
Printed Circuit Board (PCB)
Most promotional memory products (flash drives given away at trade shows) will use a two layer printed circuit board. Two layer boards are bad for use with any USB device, including a flash drive. The USB specification requires four layers for a product to be made to specification. A four layer board will include the, much needed, grounding plane of the PCB to insure transmission without interference from the trace lines. A two layer board is at a much greater risk of not performing as it should. If you received a USB at a trade show, don’t consider that device for “long term” or “important” storage options.
This is an image of a four layer USB flash drive by Nexcopy with Micron memory with write speeds of 12MB/s
Flash memory used in the production of USB drives stems from a sea of unknown factors. Flash drives are the bottom of the barrel when it comes to NAND memory as part of the BOM (bill of material). All the good quality NAND memory is used for more expensive products like phones, set-top boxes, communications hardware, etc… and the manufacturer of USB flash drives, is typically, the last tier of manufacturing consumption. With that in mind, one trick the flash manufacturers use, is down-sizing the memory wafer (NAND chip). Let us provide an example: Toshiba is the world’s largest memory manufacturer, and after production of say a 64GB chip, they test it. If the quality of the silicon cells in the chip are below a certain percentage, the chip gets downgraded to a 32GB chip. They test it. If the memory is still failing QC, it gets downgraded again. The process continues. So if you are dealing with a 512MB USB stick, you are dealing with the worst part of NAND memory chip. Very unreliable. The quickest way to test the quality of flash memory is test the write speed. For USB 2.0 product, if you see a write speed of 9-10MB/second or better… its’ good quality. For USB 3.0 if you see a write speed of 18-20MB/second or better you are dealing with good quality. A slow write speed means the silicon of the chip is having a harder time making the phase change (positive or negative) to save data to the memory chip.
The USB controller is the chip on the flash drive with all the brains. The USB controller is the gate keeper between the host computer and the USB stick. The chip allows the host computer to read or write data to and from the flash memory on the flash drive. Because the USB controller is the brain of the flash drive, it’s important to have a controller that performs well and is reliable. One of the most important features of the USB controller is wear leveling. This is also one of the most important aspects for defining the lifespan of a USB flash drive. More about wear leveling in a bit. For now, the important point is understanding the compatibility of the USB controller to that of the flash memory. The NAND memory market is very fast pasted. New technology is always developing. For this reason, the firmware inside the USB controller is very important. The firmware “marries” the flash memory to the device and creates a usable flash drive. There are many flavors of firmware for a single controller and it all boils down to how often the USB manufacturer updates those firmware tools. It is very possible to load firmware that is not optimized for the NAND memory used in the production of the flash drive. It’s also very possible the firmware is set for a different objective, for example, the firmware was set to be optimized for capacity rather than read/write speeds. The amount of control the USB factory has with these firmware tools is mind-blowing. The firmware tools are used to configure the USB stick to exactly what they want. In summary, there is no real way to test the quality of the USB controller and it’s firmware other than having an intimate knowledge and relationship with the actual manufacturer of the USB flash drive. The point to explaining the function of a USB controller is to show what a large impact it has on the overall performance of the drive.