The CEO who invented an online tool you see every day gave his tech to Yahoo for free — and he doesn't regret it

Luis von AhnLuis Von Awn graduated from Carnegie Mellon University in 2005 with a PhD in computer science.

  • Luis Von Ahn is a recipient of the MacArthur Fellowship, also known as a “Genius Grant,” and cofounded the language-learning app Duolingo.
  • Von Ahn created the cyber-security technology captcha to distinguish a human from a robot – and then gave it to Yahoo for free.
  • Today, nearly every server uses recaptcha, the second version of captcha.

If you’ve ever confirmed while you’re online that you are, in fact, a human, then you’ve used Luis von Ahn‘s recaptcha technology.

Von Ahn, a cofounder of language-learning app Duolingo, created the cyber-security technology as a PhD student a Carnegie Mellon University in 2000.

During his first semester, the chief scientist at Yahoo gave a talk to students on 10 problems Yahoo was trying to solve, Von Ahn said on an episode of Business Insider’s podcast,“Success! How I Did It.” After the talk, he went home and began tackling all 10 problems.

“I couldn’t come up with any great ideas for any of them, except for one,” said Von Ahn, who is a recipient of the MacArthur Fellowship, also known as a “Genius Grant.”

In 2000, Yahoo was a premier email service that had millions of users signing up for free accounts but had an overwhelming issue with spammers. At that time, a Yahoo email account limited users to send 500 emails a day.

“And if you’re a spammer, and you want it to send 10,000,000 messages, you would get a couple of million email accounts and from each one you would only send 10 messages or whatever,” Von Ahn said. “These people wrote programs to obtain millions of email accounts, and Yahoo did not know how to stop them.”

Von Ahn started working with his PhD adviser to develop a program that distinguished a human account holder from a computer program. It displays squiggly letters or numbers and requires users to type out the characters shown.

“That’s there because humans can read the distorted characters, whereas computers can’t do it as well,” Von Ahn explained. Yahoo started using the technology, called captcha – which stands for “Completely Automated Public Turing test to tell Computers and Humans Apart – to prevent automated signups.

Von Ahn handed the technology over to Yahoo for free and said he does not regret the decision. Since 2000, nearly every online server uses recaptcha, the second version of captcha.

“We were just so happy that we had made this thing that Yahoo was ready to use,” Von Ahn said. “To this day I hadn’t really much thought about making much money.”

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