"Digital rights management", DRM, is almost a standard in the e-book industry. Have copyright holders ever tried to protect physical books from scanning, for example in a way how banknotes are protected against counterfeiting?

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    Upvoting this because I think it's interesting, but I'm not sure whether it'll be considered on-topic for the site.
    – Rand al'Thor
    Commented Feb 19, 2017 at 19:19
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    Basically, they're not books of literature, but I have a couple of "code books" which are very hard to copy (and read) which allow game developers to copy protect their games back in the days before the Internet. Alas, I cannot give more than that due to my rep with this site.
    – Matthew
    Commented Apr 14, 2017 at 16:49

7 Answers 7


Look at it this way - the reason why companies need DRM is because digital files can always be copied verbatim, i.e. bit for bit. Companies cannot prevent files from being copied and re-distributed so they need DRM - a system that alters the files in a way that the contents can only be accessed under specific circumstances, e.g. by entering a license key, inserting an official CD, etc.

With hard copies, copying "files" is significantly harder, because one has to get a hold of the physical copy of the product. What was equal to hitting the 'download' button, now requires taking a stroll to the library, or paying money for an actual copy.

Oh, and some more diligent copy centres will not allow you to copy more than a certain per cent of the book. While this doesn't apply to every country, it may still be an obstacle.

Coming back to your actual question, what you are describing is called, per Wikipedia, the "analog hole". While it may be nigh-impossible to decipher a DRM-protected book, or crack a DRM-protected game, once you have a physical copy of an object there is a number of ways you can copy it. Off top of my head, I can already think of a "lamp + tripod + DSLR camera stand", which is not very hard to construct, but is good for practical purposes. Combine this with optical character recognition, and you have a fault-proof home-made analog piracy system. Why fault-proof? Because digital cameras use the same working principle as the human eye, so DRM, in this case, will be more of a double-edged stick than it is with digital content.

There are multiple technologies available, that make traditional scanning and copying impossible. For instance, there is a technology that will make "VOID" texts appear on scanned copy:

All of our paper products are protected by AuthentiGuard Pantograph 4000TM. This patented technology involves the printing of hidden text messages ("VOID", "COPY", "UNAUTHORIZED COPY", etc.) into the background of a document. Text information or other artwork is placed onto this paper. Then, when this "original" is copied of scanned, the hidden word pattern becomes visible on the duplicate. The end result - a clearly distinguishable copy that can not pass off as the original.

paper with black and white "VOID" signs all over itpaper with colour "VOID" signs all over it

Same company sells special paper for books as well, though I was unable to find examples of it being used,

On a more light-hearted note, there is a book that is printed with a special kind of ink: it is sold in an air-tight package, as the ink starts to fade upon contact with air. It is called El Libro Que No Puede Esperar - The Book That Can't Wait, This provides a good incentive to actually read the book, before it becomes blank paper.

Several photos of the same page of a book, each with the text more faded

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    That was really interesting. But it depends on UV fluorescence which assumes higher than ambient UV in the copying machine. Modern copiers tend to use white LEDs rather than a fluorescent lamp (a low pressure mercury vapour lamp lined with a fluorescent powder which emits a lot of UV) so I suspect this countermeasure is already failing.
    – Peter Wone
    Commented Feb 21, 2017 at 0:21
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    "Digital files cannot be made uncopyable, any more than water can be made not wet." - Bruce Scheier. Protecting a novel is impossible, as the last report the book can be copied by hand.
    – user598527
    Commented Feb 21, 2017 at 9:43
  • "Protecting a novel is impossible, as the last report the book can be copied by hand." I present to you the Bruno copy protection algorithm. Bruno breaks hands.
    – mccainz
    Commented Feb 21, 2017 at 19:59
  • This technology, or something very similar, was used experimentally in the early 1990s in the UK for paper driving licences. They would appear normal, but a photocopy would result in a word being displayed in the background of the copy (can't remember if the word was 'copy' or something else). Having tried it they forgot about it, then a 10~15 years later gave someone a hard time when he sent a photocopy of his licence in and they tried to claim the revealed word showed it was a fake!
    – Kickstart
    Commented Feb 22, 2017 at 12:49
  • @JFA - the website of the manufacturer is quite specific and detailed. It's UV. You could probably use the approach with IR but again white LEDS emit almost exclusively in the visible spectrum.
    – Peter Wone
    Commented Feb 23, 2017 at 3:37

This isn't against scanning specifically, but creators of ancient and medieval texts did attempt to protect their work against theft, vandalism and misattribution by writing curses on the book. You might consider this a form of early DRM.

For example, from the Wikipedia article on Book curses:

[...] Ashurbanipal, King of Assyria from 668 to 627 BCE, had the following curse written on many or all of the tablets collected at the library at Ninevah [...]:

I have transcribed upon tablets the noble products of the work of the scribe which none of the kings who have gone before me had learned, together with the wisdom of Nabu insofar as it existeth [in writing]. I have arranged them in classes, I have revised them and I have placed them in my palace, that I, even I, the ruler who knoweth the light of Ashur, the king of the gods, may read them. Whosoever shall carry off this tablet, or shall inscribe his name on it, side by side with mine own, may Ashur and Belit overthrow him in wrath and anger, and may they destroy his name and posterity in the land.

  • The curse doesn't protect against reading or duplication so it can't be considered DRM. DRM doesn't protect against deletion or destruction, it actually performs those things if it finds you wanting.
    – Agent_L
    Commented Feb 21, 2017 at 16:21
  • And of course it will have been no joke at the time. Another form of "DRM" was not to write anything down ever. The Celts, unfortunately, were one of the most notorious adherents of this school of protection of IP: they could have done it, as the Celts of France, Britain and Ireland were aware the Romans were writing, but they considered it sacrilegious: the only acceptable way to pass on knowledge was for a young person to learn it by heart from an older person. As a consequence we know very little about their culture except what was said by the Romans, their enemies. Commented Feb 22, 2017 at 19:22
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    @Agent_L It sure does - "divine rights management" Commented Feb 23, 2017 at 9:00

Back in the day, in the early 90s, I bought some software whose manual was printed on red paper, which was meant to discourage photocopying on black and white photocopiers. If you photocopied it, it would come out as a big mess because there wasn't much contrast between the print and the background.

Presumably this technique was used elsewhere too.

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    Film scripts are sometimes printed on red paper to help prevent photocopying (not that it can't be defeated with a scanner and some photoshop work, but it adds a barrier). Commented Feb 20, 2017 at 10:13
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    The original SimCity had a "red sheet" which was similarly used for copy protection. Every so often the game would ask you for the population of a certain real-world city, which you could read off a red sheet: magisterrex.wordpress.com/2010/10/22/… Commented Feb 20, 2017 at 15:26
  • A game I developed had the manual printed in "non-repro blue" (en.wikipedia.org/wiki/Non-photo_blue) on white for that reason.
    – Rich
    Commented Feb 21, 2017 at 3:23
  • The game "Oxyd" had a manual with tables that couldn't be copied well back then and in the game where different points where you need to get values from these tables. Also my certificate from school was red paper since i hadn't give back all my books.
    – Clayn
    Commented Feb 21, 2017 at 14:02
  • Joined just to upvote this. I'm pretty sure I still have at least one of these in my possession at home. There were pages in the manual with hex codes inked in non-repro blue (as @Rich says). At startup the game would request a semi-random subset of that to be typed in at the keyboard. I understand crackers got around this by hacking the code in the check, or sometimes by including a text file with the text in question.
    – T.E.D.
    Commented Feb 21, 2017 at 18:52

There's another version of DRM that you find in paper reference sources. (This where the data itself is not subject to protection.) Deliberately introduced harmless errors.

This does nothing to stop people from copying the material for personal use but it does keep them from copying it for commercial use.

"You say you didn't simply copy my street map. Please explain to the court how Silly Alley ended up in your map? As shown by this photograph there is no alley at that location."

Or encyclopedia articles that discuss a person or place that doesn't exist, same concept.


I'd say that the closest thing to copy protection that's ever included in physical books would be a Trap street.

These are fake elements included by cartographers in maps to catch people illegally stealing their work. Basically, you include a street, town, river, island etc that does not actually exist in a map that you have created, and if you later catch another publisher selling a map that includes that item, you sue them for illegally profiting from your work.

There are a number of interesting examples in this article: The Fake Places That Only Exist to Catch Copycat Mapmakers.

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    This is a duplicate of a preexisting answer.
    – msh210
    Commented Feb 22, 2017 at 17:43
  • @msh210 - as long as it's not a literal copy/paste, I don't think that it's worth it to delete it. Downvote, maybe, but not delete.
    – Mithical
    Commented Feb 22, 2017 at 19:36
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    Ironic comment, given that this is a question about mechanisms to discourage copying.
    – WBT
    Commented Feb 22, 2017 at 20:31
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    @msh210 Honestly, I must've missed Loren's answer. That said, another answer being the about the same concept shouldn't automatically disqualify it, or call for moderation. The same idea, differently expressed may be a better answer.
    – s3raph86
    Commented Feb 22, 2017 at 20:52

I have heard of movie scripts being printed on red or dark brown paper to prevent photocopying on set. Photocopiers at the time only supported full black or white, so if a colour was closer to black, it would become black. Red being closer to black than white resulted in pages being full black. But is different enough to be readable by humans. Not technically a book, but similar.

Of course that wouldn't work now days with modern cameras/scanners.

But modern cameras often see into the infrared spectrum so a layer of something the had a high reactivity for the infrared spectrum might. Cinemas have used bright infrared lights to prevent people recording the movie with a camera. Night vision on cameras is normally implemented with infrared lights. But not all cameras do this. Its probably also not to hard to filter out the infrared light.

It's worth considering that DRM on digital ebooks can still be bypassed using the exact same techniques as copying a physical book. You can scan/photograph the pages on an ebook reader or tablet for example. Of course it's generally quicker to crack the DRM and not have to bother.

In this way DRM just makes it more effort to copy than it's worth for many people. Although some people will bypass it, and you only need one since if they do it then, they can share it with everyone via the internet.

The other thing it does is reduce the quality of the copy. A scanned book might have OCR errors. It might not get formatted the same way. It might be missing metadata like the table of contents. Page numbers might end up in the text. A cam of a movie is bad quality, washed out, bad audio, framerate might be out of sync causing blurred frames. Capping a raw decoded video/audio feed will loose quality when it gets reencoded due to it going through lossy compression twice (that won't apply to lossless codecs, but that's generally only audio).


Many video game manuals have forms of copy protection in.

Some games require you to use a lookup sheet from the manual or similar. The lookup sheet is sometimes a decoder wheel (such as in Monkey Island) or printed in a way that is hard to copy (such as in Sim City)

These aren't really copy protection of manuals, however some games spread the copyright across the entire manual. The reason for copying a manual was primarily to bypass the copy protection of the game. Therefore as a sort of copy protection, they would often force you to have to copy the entire manual, which in the 90s was not a simple task as photocopy devices were not as ubiquitous as they are today. Examples are games like Lion King which required you to enter a word from a specific paragraph on a specific page in the manual, and Eye of the Beholder which had a symbol on every page and required you to enter a word from a page matching the symbol.

Both were deterrents to copying the manual by requiring you to copy the entire thing, which was a significant number of pages.

Copy protection through sheer volume is an interesting one, I think! Plus, it stops you from manually writing down the key parts, such as with a single large card, 20 minutes of laborious copying and you could get a key portion of it down.

Interestingly, the Lion King's copy protection could just be brute forced, if you found one word you could repeatedly launch the game and type in that word until eventually it was correct as it loaded quickly and prompted you immediately upon launch. The dictionary it had of page/line/word combinations was very small. Eye of the Beholder had symbols and a much bigger dictionary so it was harder to copy them manually. In addition, it prompted you after you completed the first level, so you couldn't restart the game quickly if you failed to try again.

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