Method and device for secure communication

1. A secure communication method comprising:

obtaining a secret code generated in response to a first communication device being paired with a second communication device;

obtaining a prestored product key;

generating a module key based on the secret code and the product key;

randomly generating a session key;

obtaining a key sequence number;

auto-incrementing the key sequence number;

setting a sending sequence number with an initial value of zero;

generating a key frame by performing a computation on the session key and a verification authentication code of the session key using the module key; and

sending a data packet including the key frame, the key sequence number, the sending sequence number, and a data type to the second communication device.

2. The method of claim 1 , wherein:

the first communication device is a master and the second communication device is a slave.

3. The method of claim 2 , wherein:

the first communication device is a flight controller and the second communication device is an unmanned aerial vehicle (UAV) or one or more circuits of the UAV.

4. The method of claim 3 , wherein:

the one or more circuits of the UAV includes one or more cameras and/or one or more gimbals.

5. The method of claim 1 :

wherein the data packet is a first data packet and the data type is a first data type;

the method further comprising:

repeating the following until the first communication device is powered up and restarted:

obtaining the sending sequence number;

auto-incrementing the sending sequence number;

obtaining instruction data to be sent;

generating an instruction data frame by encrypting the instruction data and a verification authentication code of the instruction data using the session key; and

sending a second data packet including the instruction data frame, the sending sequence number, and a second data type to the second communication device, the second data type indicating that the second data packet is an instruction data packet.

6. The method of claim 1 , wherein:

the product key is burned in one or more secure storages of the first communication device.

7. The method of claim 1 , wherein:

the module key is generated by performing a derivation algorithm on the secret code and the product key, the derivation algorithm including at least one of an encryption or a Message Authentication Code.

8. The method of claim 1 , wherein:

the session key is dynamically generated by using a random number generator.

9. The method of claim 1 , wherein auto-incrementing the key sequence number includes:

incrementing a value of the key sequence number by one each time the session key is generated.

10. The method of claim 1 , wherein auto-incrementing the sending sequence number includes:

incrementing a value of the sending sequence number by one each time data is sent to the second communication device or every preset time period.

11. The method of claim 1 , wherein performing the computation on the session key and the verification authentication code of the session key using the module key includes an encryption and/or a Message Authentication Code.

12. The method of claim 1 , wherein:

the module key, the sending sequence number, and the session key are stored in one or more volatile memories of the first communication device; and

the secret code and the key sequence number are stored in one or more non-volatile memories of the first communication device.

13. The method of claim 5 , wherein:

an initial value of the sending sequence number is zero;

the sending sequence number monotonically increases in response to the session key remaining unchanged; and

the sending sequence number is reset to zero in response to the session key being changed.

14. The method of claim 13 , wherein:

the session key and the sending sequence number are stored in one or more volatile memories of the first communication device.

15. A communication device comprising:

an authentication sending circuit configured to:

obtain a secret code generated in response to a first communication device being paired with a second communication device;

obtain a prestored product key;

generate a module key based on the secret code and the product key;

randomly generating a session key;

obtain a key sequence number,

auto-increment the key sequence number,

set a sending sequence number with an initial value of zero,

generate a key frame by performing a computation on the session key and a verification authentication code of the session key using the module key; and

send a data packet to the second communication device, the data packet including the key frame, the key sequence number, the sending sequence number, and a data type.

16. The device of claim 15 , wherein:

the communication device is an unmanned aerial vehicle (UAV), a circuit of the UAV, or a flight controller configured to control the UAV.

17. The device of claim 15 , wherein:

the communication device is a message sender and a message receiver.