Seamless authentication using radar

1. A method, comprising:

providing, through a radar-based authentication system, a radar field;

sensing, by the radar-based authentication system, reflections from an object in the radar field;

analyzing, by the radar-based authentication system, the reflections from the object in the radar field;

determining, based on the analysis of the reflections from the object, that the object is a person;

responsive to determining that the object is the person, sensing, by the radar-based authentication system, an identifying characteristic associated with the person; and

determining, based on the identifying characteristic associated with the person, that the person is an authorized user.

2. The method of claim 1 , further comprising:

granting the authorized user access to an electronic device via the radar-based authentication system;

determining, by the radar-based authentication system and based on another analysis of additional reflections from the authorized user, that the authorized user is engaged with the electronic device; and

responsive to determining that the authorized user is engaged with the device, maintaining access to the device by the authorized user without requiring additional authentication.

3. The method of claim 2 , further comprising:

determining, by the radar-based authentication system and based on the other analysis of the additional reflections from the authorized user, that the authorized user is not engaged with the electronic device; and

responsive to determining that the authorized user is not engaged with the electronic device, ending access to the electronic device by the authorized user.

4. The method of claim 2 , further comprising:

determining, by the radar-based authentication system, that another person has come within a threshold distance from the electronic device; and

responsive to determining that the other person has come within the threshold distance from the electronic device, ending access to the electronic device by the authorized user.

5. The method of claim 1 , further comprising sensing other reflections from the person, and wherein sensing the identifying characteristic includes analyzing the other reflections from the person.

6. The method of claim 1 , wherein the analysis of the reflections from the object further comprises:

comparing the reflections from the object to stored reference data, the stored reference data including radar-reflection profiles of human bodies; and

determining, based on the comparison, the object is a human body.

7. The method of claim 1 , wherein sensing the identifying characteristic comprises performing a radar-based facial recognition technique.

8. The method of claim 1 , wherein sensing the identifying characteristic comprises performing a radar-based breathing-pattern recognition technique.

9. The method of claim 1 , wherein the identifying characteristic associated with the person is a radar-sensed gait of the person.

10. The method of claim 1 , wherein the identifying characteristic associated with the person is a radar-sensed biometric characteristic of the person.

11. The method of claim 1 , wherein the identifying characteristic associated with the person is:

an item, worn on the person, that is detectable by the radar-based authentication system; or

a gesture that is detectable by the radar-based authentication system.

12. An apparatus, comprising:

a radar-based authentication system comprising:

a radar-emitting element configured to provide a radar field;

an antenna element configured to receive reflections from objects that are within the radar field; and

a signal processor configured to process the received reflections to provide authentication data associated with the received reflections;

one or more computer processors; and

one or more computer-readable storage media having instructions stored thereon that, responsive to execution by the one or more computer processors, perform operations comprising:

causing the radar-based authentication system to provide a radar field with the radar-emitting element;

causing the radar-based authentication system to receive reflections from an object in the radar field with the antenna element;

causing the signal processor to process the received reflections to provide authentication data for the object;

determining, based on the authentication data for the object, that the object is a person;

causing the radar-based authentication system to receive other authentication data; and

determining, based on the other authentication data that the person is an authorized user.

13. The apparatus of claim 12 , wherein the operations further comprise:

granting the authorized user access to an electronic device via the radar-based authentication system;

determining, by the radar-based authentication system and based on another analysis of additional reflections from the authorized user, that the authorized user is engaged with the electronic device; and

responsive to determining that the authorized user is engaged with the device, maintaining access to the device by the authorized user without requiring additional authentication.

14. The apparatus of claim 13 , wherein the operations further comprise:

determining, by the radar-based authentication system and based on the other analysis of the additional reflections from the authorized user, that the authorized user is not engaged with the electronic device; and

responsive to determining that the authorized user is not engaged with the electronic device, ending access to the electronic device by the authorized user.

15. The apparatus of claim 13 , wherein the operations further comprise:

determining, by the radar-based authentication system, that another person has come within a threshold distance from the electronic device; and

responsive to determining that the other person has come within the threshold distance from the electronic device, ending access to the electronic device by the authorized user.

16. A method, comprising:

providing, through a radar-based authentication system, a radar field;

sensing, by the radar-based authentication system, reflections from an object in the radar field;

analyzing, by the radar-based authentication system, the reflections from the object in the radar field;

determining, based on the analysis of the reflections from the object, that the object is a person;

responsive to determining that the object is the person, sensing, by an identification system comprising at least one non-radar sensor, an identifying characteristic associated with the person; and

determining, based on the identifying characteristic associated with the person, that the person is an authorized user.

17. The method of claim 16 , further comprising: responsive to determining that the object is the person, activating the identification system.

18. The method of claim 16 , wherein the analysis of the reflections from the object further comprises:

comparing the reflections from the object to stored reference data, the stored reference data including radar reflection profiles of human bodies; and

determining, based on the comparison, the object is a human body.

19. The method of claim 16 , wherein sensing the identifying characteristic comprises performing, by the identification system:

an image-based facial recognition technique; or

an image-based tattoo recognition technique.

20. The method of claim 14 , wherein the identifying characteristic is an image-based biometric characteristic of the person.