User authentication systems and methods

1. A method comprising:

detecting, by a user authentication system, a touch input on a lock screen of a mobile device while the lock screen displays a notification of an incoming voice call;

determining, by the user authentication system, a total distance of movement of the touch input across the lock screen;

determining, by the user authentication system based on the determining of the total distance, that the touch input satisfies an end-user-defined authentication key requirement that includes an end-user-defined setting specifying that a direction of a vector representative of the touch input across the lock screen will not be considered as part of the end-user-defined authentication key requirement; and

facilitating, by the user authentication system based on the determining that the touch input satisfies the end-user-defined authentication key requirement, a pick-up of the incoming voice call,

wherein, based on the end-user-defined setting, the determining that the touch input satisfies the end-user-defined authentication key requirement is performed irrespective of a direction in which the touch input is directed across the lock screen.

2. The method of claim 1 , wherein:

the determining of the total distance of the movement of the touch input across the lock screen includes determining a distance associated with the vector that is representative of the touch input.

3. The method of claim 1 , wherein the determining of the total distance of the movement of the touch input across the lock screen includes summing a plurality of distances associated with a plurality of vectors that are representative of the touch input.

4. The method of claim 1 , wherein the determining that the touch input satisfies the end-user-defined authentication key requirement includes comparing the total distance to an authentication key that is defined in advance by an end user of the mobile device and that specifies a distance threshold required for authentication.

5. The method of claim 4 , wherein the authentication key further specifies a number of vectors required in the touch input for authentication.

6. The method of claim 4 , wherein the determining that the touch input satisfies the end-user-defined authentication key requirement further includes determining that the total distance falls within an end-user-defined tolerance of the distance threshold specified by the authentication key.

7. The method of claim 1 , further comprising providing, by the user authentication system for display on the lock screen of the mobile device, a distance indicator that indicates, in real time, a current distance of movement as the touch input moves across the lock screen.

8. The method of claim 1 , further comprising:

providing, by the user authentication system for display on a touch screen of the mobile device, a settings screen that prompts an end user of the mobile device to define an authentication key;

detecting, by the user authentication system, an authentication-key-defining touch input across the settings screen;

determining, by the user authentication system based on the authentication-key-defining touch input, a total distance of movement of the authentication-key-defining touch input across the settings screen; and

defining, by the user authentication system based on the total distance of movement of the authentication-key-defining touch input, the authentication key.

9. The method of claim 8 , further comprising:

providing, by the user authentication system for display on the touch screen of the mobile device, an additional settings screen that includes one or more options to modify the authentication key, the one or more options comprising at least one of an option to modify a distance threshold specified by the authentication key, an option to modify a number of vectors associated with the authentication key, and an option to define an end-user-defined tolerance of the distance threshold specified by the authentication key.

10. The method of claim 1 , embodied as computer-executable instructions on at least one non-transitory computer-readable medium.

11. A method comprising:

detecting, by a user authentication system while a lock screen of a mobile device displays a notification of an incoming voice call, a movement of the mobile device;

determining, by the user authentication system, that the movement of the mobile device satisfies an end-user-defined authentication key requirement that includes an end-user-defined setting specifying that a direction of a vector representative of the movement of the mobile device will not be considered as part of the end-user-defined authentication key requirement; and

facilitating, by the user authentication system based on the determining that the movement of the mobile device satisfies the end-user-defined authentication key requirement, a pick-up of the incoming voice call,

wherein, based on the end-user-defined setting, the determining that the movement of the mobile device satisfies the end-user-defined authentication key requirement is performed irrespective of a direction in which the mobile device moves.

12. The method of claim 11 , wherein the determining that the movement of the mobile device satisfies the end-user-defined authentication key requirement comprises:

determining a total distance of the movement of the mobile device; and

determining that the total distance of the movement of the mobile device satisfies the end-user-defined authentication key requirement.

13. The method of claim 11 , wherein the determining that the movement of the mobile device satisfies the end-user-defined authentication key requirement comprises:

identifying a set of vectors representative of the movement of the mobile device; and

determining that attributes of the set of vectors representative of the movement of the mobile device satisfy the end-user-defined authentication key requirement.

14. The method of claim 11 , further comprising:

providing, by the user authentication system for display on a touch screen of the mobile device, a settings screen that prompts an end user of the mobile device to define an authentication key;

detecting, by the user authentication system, an authentication-key-defining movement of the mobile device;

determining, by the user authentication system based on the authentication-key-defining movement of the mobile device, one or more attributes of the authentication-key-defining movement of the mobile device; and

defining, by the user authentication system, the authentication key based on the one or more attributes of the authentication-key-defining movement of the mobile device.

15. The method of claim 14 , further comprising:

providing, by the user authentication system for display on the touch screen of the mobile device, an additional settings screen that includes one or more options to modify the authentication key, the one or more options comprising at least one of an option to modify a distance threshold specified by the authentication key, an option to modify a number of vectors associated with the authentication key, and an option to define an end-user-defined tolerance of the distance threshold specified by the authentication key.

16. The method of claim 11 , embodied as computer-executable instructions on at least one non-transitory computer-readable medium.

17. A system comprising:

at least one physical computing device that:

detects a touch input on a lock screen of a mobile device while the lock screen displays a notification of an incoming voice call;

determines a total distance of movement of the touch input across the lock screen;

determines, based on the determined total distance, that the touch input satisfies an end-user-defined authentication key requirement that includes an end-user-defined setting specifying that a direction of a vector representative of the touch input across the lock screen will not be considered as part of the end-user-defined authentication key requirement; and

facilitates, after the at least one physical computing device determines that the touch input satisfies the end-user-defined authentication key requirement, a pick-up of the incoming voice call,

wherein, based on the end-user-defined setting, the at least one physical computing device determines that the touch input satisfies the end-user-defined authentication key requirement irrespective of a direction in which the touch input is directed across the lock screen.

18. The system of claim 17 , wherein:

the at least one physical computing device determines the total distance of the movement of the touch input across the lock screen by determining a distance associated with the vector that is representative of the touch input.

19. The system of claim 17 , wherein the at least one physical computing device determines the total distance of the movement of the touch input across the lock screen by summing a plurality of distances associated with a plurality of vectors that are representative of the touch input.