Witness

In 2000, as the internet expanded, websites faced a growing challenge to stop spam bots from flooding their systems.To separate humans from machines, researchers at the United States’ Carnegie Mellon University in Pittsburgh, Pennsylvania, created the Completely Automated Public Turing test.From its early development to its evolution into reCAPTCHA it continues to block millions of automated attacks every day.Ashley Byrne speaks to computer scientist Andrei Broder, who played a key role in developing the concepts that helped shape this technology.A Made in Manchester production. Eye-witness accounts brought to life by archive. Witness History is for those fascinated by the past. We take you to the events that have shaped our world through the eyes of the people who were there. For nine minutes every day, we take you back in time and all over the world, to examine wars, coups, scientific discoveries, cultural moments and much more. Recent episodes explore everything from the death of Adolf Hitler, the firs