Patent ID: 9699176
Date: 2017-07-04
CPC Classifications: G06F,H04L

Claim:
1. A computer system for determining if a user of a computer system is a human, the computer system comprising: one or more computer processors; one or more computer readable storage media; and program instructions stored on the computer readable storage media for execution by at least one of the one or more processors, the program instructions comprising: program instructions to receive an indication that a computer security program is needed, and in response, acquiring, by one or more processors, at least one image depicting a first string of characters including at least a first set of one or more characters, and a second set of one or more characters; program instructions to assign a first substitute character to be used as input for each of the second set of one or more characters, wherein the first substitute character is a different character than any of the second set of one or more characters; program instructions to present the at least one image, an indication of the first substitute character, and an indication of when to use the first substitute character to the user, program instructions to receive a second string of characters from the user; program instructions to determine whether the second string of characters substantially matches, within a predetermined threshold, the first string of characters based on the first substitute character assigned to each of the second set of one or more characters, wherein the determination further comprises: program instructions to determine that the second string of characters substantially matches, within a second predetermined threshold, the first string of characters, based on the weighting factor associated with each character within the second string of characters, and responsive to determining that the second string of characters substantially matches, within a second predetermined threshold, the first string of characters, based on the weighting factor associated with each character within the second string of characters, program instructions to determine that the user of the computer system is a human.