Patent ID: 9742751
Date: 2017-08-22
CPC Classifications: G06F,H04L

Claim:
1. An authentication system, comprising: a non-transitory memory configured to store a plurality of stimulus challenges, a respective first count associated with each stimulus challenge of the plurality of stimulus challenges, and a respective second count associated with each stimulus challenge of the plurality of stimulus challenges; a network interface component; and one or more hardware processors coupled to the non-transitory memory and the network interface component, the one or more hardware processors configured to execute instructions to cause the authentication system to perform operations comprising: selecting a first stimulus challenge from the plurality of stimulus challenges; transmitting, using the network interface component, the first stimulus challenge to a user; receiving, via the network interface component, a response to the first stimulus challenge; incrementing the respective first count associated with the first stimulus challenge in cases where the first stimulus challenge is transmitted and the response is received; incrementing the respective second count associated with the first stimulus challenge in cases where a successful response to the stimulus challenge is detected and an authentication session including the first stimulus challenge fails; determining a ratio of the respective second count to the respective first count; comparing the ratio to a threshold; removing the first stimulus challenge from the plurality of stimulus challenges when the ratio is greater than the threshold; and outputting an indication that the first stimulus challenge is statistically vulnerable to attack.