Captchas of the Future

Captchas of the Future

Captchas are good at weeding out spam, because they rely on tasks that humans do well and computers don’t, and because spammers use bots.

But as spammers get more sophisticated, their tools will get better and better at reading letters and numbers, so we’ll need to use new types of problems to keep them out:

Max was born May 12, 1947. His son was born on Max’s 22nd birthday.
How old is Max’s son?

points out that this would also be a good way of keeping out the riff-raff, such as people who can’t write a sentence without doing violence to the English language:

Fill in the blanks:
the person keys I found?
Tell them I found keys over .

(Adjust for whatever language your site is in.)

Or people who just don’t belong on your site:

And since spammers now get email subject lines from news headlines, perhaps it’s time to turn the tables on them:

Complete this sentence:
was recently named in a government corruption scandal that has embroiled several high-ranking officials.

Okay, maybe not that last one: for a captcha to work, there have to be at least some wrong answers.