Why Are Bots Unable to Check "I Am Not a Robot" Checkboxes?

iStock.com/Oleksandr Hruts
iStock.com/Oleksandr Hruts

Oliver Emberton:

How complicated can one little checkbox be? You can't even imagine!

For starters, Google invented an entire virtual machine—essentially a simulated computer inside a computer—just to run that checkbox.

That virtual machine uses Google's own language, which they then encrypt. Twice.

But this is no simple encryption. Normally, when you password protect something, you might use a key to decode it. Google’s invented language is decoded with a key that is changed by the process of reading the language, and the language also changes as it is read.

Google combines (or hashes) that key with the web address you’re visiting, so you can’t use a CAPTCHA from one website to bypass another. It further combines that with “fingerprints” from your browser, catching microscopic variations in your computer that a bot would struggle to replicate (such as CSS rules).

All of this is done just to make it hard for you to understand what Google is even doing. You need to write tools just to analyze it. (Fortunately people did just that).

It turns out that these checkboxes record and analyze a lot of data, including: Your computer’s timezone and time; your IP address and rough location; your screen size and resolution; the browser you’re using; the plugins you’re using; how long the page took to display; how many key presses, mouse clicks, and tap/scrolls were made; and ... some other stuff we don’t quite understand.

We also know that these boxes ask your browser to draw an invisible image [PDF] and send it to Google for verification. The image contains things like a nonsense font, which (depending on your computer) will fall back to a system font and be drawn very differently. They then add to this a 3D image with a special texture, which is drawn in such a way that the result varies between computers.

Finally, these seemingly simple little checkboxes combine all of this data with their knowledge of the person using the computer. Almost everyone on the Internet uses something owned by Google—search, mail, ads, maps—and as you know, Google Tracks All Of Your Things™️. When you click that checkbox, Google reviews your browser history to see if it looks convincingly human.

This is easy for them, because they’re constantly observing the behavior of billions of real people.

How exactly they check all this information is impossible to know, but they’re almost certainly using machine learning (or AI) on their private servers, which is impossible for an outsider to replicate. I wouldn’t be surprised if they also built an adversarial AI to try to beat their own AI, and have both learn from each other.

So why is all this hard for a bot to beat? Because now you’ve got a ridiculous amount of messy human behaviors to simulate, and they’re almost unknowable, and they keep changing, and you can’t tell when. Your bot might have to sign up for a Google service and use it convincingly on a single computer, which should look different from the computers of other bots, in ways you don’t understand. It might need convincing delays and stumbles between key presses, scrolling and mouse movements. This is all incredibly difficult to crack and teach a computer, and complexity comes at a financial cost for the spammer. They might break it for a while, but if it costs them (say) $1 per successful attempt, it’s usually not worth them bothering.

Still, people do break Google’s protection [PDF]. CAPTCHAs are an ongoing arms race that neither side will ever win. The AI technology that makes Google’s approach so hard to fool is the same technology that is adapted to fool it.

Just wait until that AI is convincing enough to fool you.

Sweet dreams, human.

This post originally appeared on Quora. Click here to view.

What Is the Shelf Life of Donated Eyes?

iStock.com/Pedro_Turrini
iStock.com/Pedro_Turrini

Zoe-Anne Barcellos:

I can only answer for cornea and eye donation.

The FDA does all oversight (no pun intended) of organ disposition.

The main organs—heart, liver, pancreas, lungs, etc.—are transplanted within hours. They are just not viable if they are not being perfused constantly.

The other tissues—like bone, skin, tendons, etc.—do not need to be transplanted immediately. But I am not sure on the regulations of when they need to be transplanted.

With the eyes, there are four tissues that can be recovered.

We recover whole eyes for research and education purposes. These usually go much faster, but we can hold them up to a year.

Conjunctiva can also be recovered; conjunctiva is a clear covering over most of the eye (it is what gets irritated when you have pink eye). I have been working as a recovery tech for five years, and our office has not had a request for "conj" in all that time. I believe it is mostly used for research, but I could be wrong.

Sclera is the white area of your eye. It is fairly thick and flexible. If you have ever touched a reptile egg, that is what it reminds me of. We recover sclera for transplant. They use it for several things, but mainly to patch punctures. Similar to if you pop the inner tube of your bike and repair it. Sclera can also be used to repair ear drums. We can hold on to this for up to a year.

The main thing we recover is corneas. In the U.S., we must transplant these within seven days of recovery. (Recovery is usually within hours of death, but we can push it up to 20 hours after if needed.) Sometimes we have more corneas than we need, and then they are shipped overseas and transplanted up to 14 days after recovery. There is no real different outcome with the later transplant time, but the FDA in the U.S. made the rules. (You can sign up to be an organ, tissue, and eye donor here.)

This post originally appeared on Quora. Click here to view.

Why Are There No Snakes in Ireland?

iStock
iStock

Legend tells of St. Patrick using the power of his faith to drive all of Ireland’s snakes into the sea. It’s an impressive image, but there’s no way it could have happened.

There never were any snakes in Ireland, partly for the same reason that there are no snakes in Hawaii, Iceland, New Zealand, Greenland, or Antarctica: the Emerald Isle is, well, an island.

Eightofnine via Wikimedia Commons // Public Domain

Once upon a time, Ireland was connected to a larger landmass. But that time was an ice age that kept the land far too chilly for cold-blooded reptiles. As the ice age ended around 10,000 years ago, glaciers melted, pouring even more cold water into the now-impassable expanse between Ireland and its neighbors.

Other animals, like wild boars, lynx, and brown bears, managed to make it across—as did a single reptile: the common lizard. Snakes, however, missed their chance.

The country’s serpent-free reputation has, somewhat perversely, turned snake ownership into a status symbol. There have been numerous reports of large pet snakes escaping or being released. As of yet, no species has managed to take hold in the wild—a small miracle in itself.

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