US Patent 9,990,040, filed September 25, 2015, issued June 5, 2018.download pdf
A system performs haptic challenge-response functionality. The system generates one or more haptic effects, provides the one or more haptic effects as a haptic challenge question to a user via a haptic output device, and receives an answer from the user corresponding to the haptic challenge question. The system then determines, based on a model of human perception, whether the answer corresponds to a correct answer to the haptic challenge question. One embodiment predicts the correct answer to the haptic challenge question, compares the correct answer with the answer received from the user, and determines that the user is a human when the answer matches the correct answer. One embodiment repeats the generating, the providing, the receiving, the predicting, and the comparing when the answer does not match the correct answer.