Patent 10187421 was granted and assigned to PayPal on January, 2019 by the United States Patent and Trademark Office.
A self-updating system for defending against a cyberattack requests connected devices to solve a problem that is created in a random manner. The problems are created in a manner such that the system can determine whether the client device is being used as part of a cyberattack based on how the client device responds to the problems.