A new study suggests that text-based CAPTCHAs are no longer safe. Researchers from Northwest University and Peking University in China, and Lancaster University in the U.K., say they developed a machine learning algorithm that can crack most text-based CAPTCHAs within 0.05 seconds. Northwest University's Fang Dingyi said the algorithm exhibited a more than 50% success rate on decoding text-based CAPTCHA schemes used by 50 popular websites within that timeframe. The tool uses a generative adversarial network that teaches a CAPTCHA generator program to produce large numbers of CAPTCHAs to train a solver. Said Fang, "This research suggests one can easily launch an attack on a new CAPTCHA scheme using [artificial intelligence]. It means that this first defense of many websites is no longer reliable."