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Comment by rav

5 days ago

> For example, it would be interesting to incorporate Ghost Font into CAPTCHA systems, as most systems are easily solved by AI today.

It seems to me like it should be easy enough to take Ghost Font, apply normal video compression techniques, and analyze the compressed signal to recover the visual outline of the letters, which you would then analyze with OCR (or an AI I guess ...). In other words, a novel CAPTCHA technique but not necessarily "fundamentally more difficult" than existing CAPTCHA techniques, once the cat-and-mouse game gets going.

I took just two screenshots and applied some filters and got

https://fingswotidun.com/images/GhostFont_2_samples.jpg

https://fingswotidun.com/images/GhostFont_b_2_samples.jpg

An AI would be able to take consecutive frames rather than hamfistedly pressing the screenshot button, then accumulate enough samples to clearly make out the text from a clip shorter than the time it would take for a human to read it.

  • "Written in ghost font" is the decoy message. Your filters got those words.

    The real message is "only a human can read this" and your filters didn't get these words.

    (But I think there should be a way to catch them)

Yes, it may be useful to replace current CAPTCHA, but this does not provide the positive side-effects of CAPTCHA where user-submitted data is used to train the unknown images or reinforce the labelling of existing image segments.

  • It’s been years since captcha was contributing to labeling.

    • Indeed, they don't contribute to labeling. The self driving companies figured out long ago that machine learning is way too expensive. Instead, Google is using its large network of willing humans to inform automated driving decisions in real time.

      So the next time you're asked to click the pictures with the bicycles or traffic lights? Please do so before it's too late.

      (/s, if that's necessary)

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