Patent ID: 8812668

Claim:
A computer-implemented system for implementing human interactive proof (HIP) challenges, the computer-implemented system comprising: a processor; a memory storing processor-executable instructions comprising a HIP challenge component and a HIP response evaluator component, wherein: the human interactive proof (HIP) challenge component displays a HIP challenge to a first user in response to receiving a user request to access a service; the HIP response evaluator component determines if the first user is human or non-human based on a response to the HIP challenge and a previous response pattern of a known user, if the first user is associated with the known user, the previous response pattern of the known user being obtained by tracking the known user over multiple sessions; and wherein if the response to the HIP challenge is correct, the HIP response evaluator component compares the previous response pattern of the first user to known response patterns of machines and humans to calculate a probability that the first user is human and determine if the first user is likely a human based on the probability, and if so, the HIP response evaluator component allows the first user access to the service.