ESTABLISHING TRUSTED RELATIONSHIPS FOR MULTIMODAL WIRELESS POWER TRANSFER

• US 20170256980A1
• Filed: 05/24/2017
• Published: 09/07/2017
• Est. Priority Date: 03/29/2012
• Status: Active Grant

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: SINGH, Manjit, HAO, Jianbin, SHAO, Zhuyan, STEPHENS, Christopher
• Granted Patent: US 10,756,558 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

In accordance with aspects of the present invention, a first wireless power enabled device includes a transceiver and control logic. The transceiver includes a plurality of switches coupled in a full-bridge configuration with a resonant tank circuit. The control logic is configured to detect a presence of a second wireless power enabled device, establish a trusted relationship with the second wireless power enabled device, determine an operating mode of the first wireless power enabled device selected from a transmit mode or a receive mode, and drive the plurality of switches to operate the resonant tank circuit in the determined operating mode. The first wireless power enabled device may further include a memory that stores a copy of a first key associated with the first wireless power enabled device and a copy of a second key associated with the second wireless power enabled device

Claims

1. A first wireless power enabled device, comprising:

a transceiver including a plurality of switches coupled in a full-bridge configuration with a resonant tank circuit; and

control logic configured to;

detect a presence of a second wireless power enabled device;

establish a trusted relationship with the second wireless power enabled device;

determine an operating mode of the first wireless power enabled device, the operating mode being selected from a transmit mode or a receive mode; and

drive the plurality of switches to operate the resonant tank circuit in the determined operating mode.

2. The first wireless power enabled device of claim 1, wherein the control logic is configured to establish the trusted relationship prior to determining the operating mode.

3. The first wireless power enabled device of claim 1, wherein the control logic is configured to establish the trusted relationship after determining the operating mode and prior to driving the plurality of switches.

4. The first wireless power enabled device of claim 1, further comprising a memory that stores a copy of a first key associated with the first wireless power enabled device and a copy of a second key associated with the second wireless power enabled device.

5. The first wireless power enabled device of claim 4, wherein the copy of the first key and the copy of the second key are stored securely.

6. The first wireless power enabled device of claim 4, wherein the control logic is further configured to establish the trusted relationship by verifying that the second wireless power enabled device has matching copies of the first and second keys.

7. The first wireless power enabled device of claim 4, wherein the memory stores copies of one or more additional keys associated with other devices with which trusted relationships are established.

8. The first wireless power enabled device of claim 4, wherein the first key and the second key include binary vectors with N elements each.

9. The first wireless power enabled device of claim 8, wherein the binary vectors are randomly generated.

10. The first wireless power enabled device of claim 1, further comprising a random number generator that provides one or more random numbers to the control logic when establishing the trusted relationship.

11. The first wireless power enabled device of claim 1, wherein the control logic is further configured to verify that the second wireless power enabled device is a member of a shared charging pool of devices based on the trusted relationship.

12. The first wireless power enabled device of claim 1, wherein the control logic is further configured to determine the operating mode based on information associated with the trusted relationship.

13. A method comprising:

determining an operating mode of a first wireless power enabled device that includes a plurality of switches coupled in a full-bridge configuration with a resonant tank circuit, wherein the operating mode is selected from a receive mode and a transmit mode;

establishing a trusted relationship between the first wireless power enabled device and a second wireless power enabled device; and

when the determined operating mode is the receive mode, driving the plurality of switches to generate a wireless power signal that transmits power to the second wireless power enabled device.

14. The method of claim 13, wherein establishing the trusted relationship comprises:

generating a first message;

encrypting the first message to generate a first encrypted message;

sending the first encrypted message to the second wireless power enabled device;

receiving a second encrypted message from the second wireless power enabled device;

decrypting the second encrypted message to generate a second message;

determining whether the first and second messages match; and

when the first and second messages match, determining that the authentication passed and establishing the trusted relationship.

15. The method of claim 14, wherein generating the first message includes generating a random binary value with N elements, where N is an integer.

16. The method of claim 15, wherein encrypting the first message includes computing a first function using the random value and a first key as inputs, where the first key is a binary vector with N elements.

17. The method of claim 16, wherein decrypting the second encrypted message includes computing a second function using the second encrypted message and a second key as inputs, where the second key is a binary vector with N elements that is different from the first key, and wherein the second function is an inverse function of a third function used by the second wireless power enabled device to generate the second encrypted message.

18. The method of claim 14, wherein sending the first encrypted message includes modulating a wireless power signal that is used to transfer power between the first and second wireless power enabled devices.

19. The method of claim 14, further comprising:

receiving a third encrypted message from the second wireless power enabled device;

decrypting the third encrypted message to generate a third message;

encrypting the third message to generate a fourth encrypted message; and

sending the fourth encrypted message to the second wireless power enabled device.

20. A first wireless power enabled device comprising:

a transceiver including a plurality of switches coupled in a full-bridge configuration with a resonant tank circuit;

a secure storage that includes copies of two or more digital keys; and

control logic configured to;

detect a presence of a second wireless power enabled device;

authenticate the second wireless power enabled device using the two or more digital keys;

negotiate with the authenticated second wireless power enabled device to determine an operating mode of the first wireless power enabled device, the operating mode being selected from a transmit mode or a receive mode;

drive the plurality of switches to operate the resonant tank circuit in the determined operating mode.