1. A method comprising: (AA) monitoring input-user interactions of a user, that utilizes an electronic device to access a computerized service; (BB) analyzing said input-user interactions, and identifying a particular word that the user typed multiple times in a user-specific typing manner; subsequently, (CC) determining that a current user, that (i) fails to perform an authentication process for accessing said computerized service or (ii) requests to perform a reset process for a user-authentication factor of said computerized service, is a genuine user that is authorized to reset said user-authentication factor of said computerized service, by performing: (a) constructing a unique multiple-word phrase, which comprises (i) said particular word that was identified in step (BB), and also (ii) one or more other words; and presenting to the current user a fresh task that requires the current user to type said unique multiple-word phrase; (b) monitoring a fresh manner in which the current user types said unique multiple-word phrase; (c) determining whether or not fresh typing of said unique multiple-word phrase as monitored in step (b), exhibits during typing of said particular word the user-specific typing manner that was identified in step (BB) during repeated previous typing of said particular word; (d) if the determining of step (c) is positive, then determining that the current user is the genuine user that is authorized to reset said user-authentication factor of said service.