Method, device, and system of differentiating among users based on responses to injected interferences

A method comprising:

• determining whether a user, who utilizes a computing device to interact with a computerized service, is either an authorized user or an attacker;
• wherein the determining comprises:
• generating a temporary input/output interference that causes an anomaly between (A) input gestures that the user performs via an input unit of said computing device, and (B) output that is displayed on a display unit of said computing device as a result of the input gestures;
• wherein the temporary input/output interference is a binary-type interference defined to trigger one of two possible manual user responses,
• wherein the two possible manual user responses comprise:
• a first possible manual user response that is performed by a majority of a general population of users;
• and a second possible manual user response that is performed by a minority of the general population of users;
• based on a level of uniqueness in the general population of users, of a particular response-to-interference that is identified in input-unit interactions of said user, determining whether or not to re-use said temporary input/output interference in subsequent usage sessions of said user;
• wherein the method further comprises:
• presenting to a user of an electronic device a screen comprising content and an advertisement;
• injecting a temporary input/output aberration that causes an on-screen pointer, that is on route to click within said advertisement, to deviate from its regular route;
• tracking user interactions with an input unit of said electronic device in response to said temporary input/output aberration;
• determining whether said user performed manual correction operations that fix said temporary input/output aberration;
• in response to determining that said user performed manual correction operations that fixed said temporary input/output aberration, determining that a click of said user within said advertisement was performed by a genuine user and not by a click-fraud mechanism;
• in response to determining that said user performed manual correction operations that did not fix said temporary input/output aberration, determining that a click of said user within said advertisement was performed by a click-fraud mechanism.