New Technology Thwarts Image Thieves Using… Sudoku?


A Malaysian researcher may have dealt a major blow to image thieves by using the mathematical formulas behind Sudoku puzzles to create hidden, super-strong watermarks.

Information security specialist Shamsul Khalid of the University Tun Hussein Onn Malaysia was looking for a more robust way to identify and protect digital images when he realized a flexible mathematical base was staring right at him from the newspaper puzzle page.

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Khalid and colleagues overlaid evenly distributed 9×9 Sudoku puzzles across several dozen images. The puzzles, invisible to the human eye, wreaked havoc with Web programs that crop and distort copyrighted images to aid unauthorized distribution.

The puzzles defeated 94 percent of image-stealing bots, with reliability increasing further when puzzles were expanded to a 16×16 grid. Current anti-cropping watermarks top out at around 75 percent reliability.

Khalid presented his research in a paper published by the International Journal of Grid and Utility Computing. No word yet on when or how the technology might be incorporated into a usable product.

(via Red Orbit)

Image credit: Sudoku by Steve Rhodes and Large copyright graffiti… by Horia Varlan

  • CurrentCo

    Shut up and take my money!

  • 3ric15

    What does it mean by the puzzles being “invisible to the human eye” if they’re “in” the pictures?

  • Cinekpol

    Clever. If they can develop this into something that an end-user can use – just run a kickstarter campagin and swim in cash. ;)
    (I would guess though that it wouldn’t survive resizing and/or high compression levels what in the end makes it as useless as any other alternative out there)

  • alex

    i would assume like those photos which have watermarks at the bottom of the photo, when you try and crop the photo the entire thing becomes pixelated and unusable

  • McGraffix

    It would probably survive resizing & compression only if you are the legitimate owner or user of the image, as you’d have or be given the ‘key’ to unlock – or in this context ‘solve’ might be a better word to use – the puzzle that will allow you to.
    No use protecting your images if this technique would compromise your own workflow, as it would if, after watermarking, you’d have to always go back to your original image anytime you’d want to alter something.
    The guy probably thought about that too (or he should start ;) ).

  • nullhogarth

    Can you show us an example of such an image, alex? I’ve never seen an image that couldn’t be cropped.

  • rz67

    Tahniah saudara! Tabik.

  • nullhogarth

    That’s easy for you to say.

  • Could be

    could also be built into the image coding? when screwed up it screws up the image?

  • Timothy Smitley

    All you have to do is save your final images without the filter in one folder, and then save your final images with the filter in another folder.

  • pKami

    Data can be hidden in an image effectively. This approach is called Steganography (read more on Wikipedia), and it’s more popular than you think.

  • Urs Basteck

    awesome Sudoku skills right there! :D

  • Tom Waugh

    Whilst applauding Shamsul and his colleagues, I am sure that this would only work on the original image complete with it’s data. it wouldn’t work however if the thief made a screenshot of the image. Also, what happens when an image is uploaded to Facebook where the data is stripped out?