Image processing method and client device, image authentication method and server device

1. An image processing method for a client, comprising:

photographing an object to obtain a first image;

sending a key acquiring request to a server and receiving a key from the server;

generating a second image for authentication based on the key and the first image; and

sending the second image for authentication to the server,

wherein the key is generated in real time by the server in response to the key acquiring request and the key changes with time, and

wherein the server determines a time difference between a time at which the key is sent to the client and a time at which the second image for authentication is received from the client, and determines that the authentication is failed in case that the time difference exceeds a key expiration period.

2. The image processing method of claim 1 , wherein the second image is generated by a steganography algorithm based on the key and the first image.

3. The image processing method of claim 2 , wherein the second image is generated by modifying the first image directly.

4. The image processing method of claim 2 , wherein the second image is synthesized by the steganography algorithm based on the key and the first image,

wherein the image processing method further comprises: deleting the first image.

5. The image processing method of claim 2 , wherein the steganography algorithm is executed in an encrypted mode.

6. The image processing method of claim 1 , further comprising:

displaying the second image after generating the second image; and

receiving a user operation;

wherein said sending the second image to the server is performed in case that the user operation indicates to send the second image.

7. The image processing method of claim 1 , further comprising:

receiving an authentication result on the second image from the server;

accumulating times of failure in case that the authentication result indicates that the authentication is failed; and

clearing the times of failure in case that the authentication result indicates that the authentication is succeeded.

8. The image processing method of claim 7 , further comprising:

locking the client in case that the times of failure reach a first predefined threshold.

9. The image processing method of claim 1 , wherein the key is received from the server through an encrypted channel and the second image is sent to the server through the encrypted channel.

10. The image processing method of claim 1 , wherein the client accesses the server via a device; and

wherein sending a key acquiring request to a server includes sending a device identification of the client in the key acquiring request to the server.

11. The image processing method of claim 1 , wherein the key received from the server is a unique key generated based on the key acquiring request.

12. An image authentication method for a server, comprising:

receiving a key acquiring request from a client;

generating a key and sending the key to the client in response to the key acquiring request;

receiving a second image for authentication from the client; and

authenticating the second image for authentication by using the key,

wherein the second image is generated based on the key and a first image obtained through photographing an object by the client,

wherein the key changes with time, and

wherein the image authentication method for a server further comprises:

determining a time difference between a time at which the key is sent to the client and a time at which the second image for authentication is received from the client; and

determining that the authentication is failed in case that the time difference exceeds a key expiration period.

13. The image authentication method of claim 12 , wherein said authenticating the second image for authentication by using the key comprises:

generating a disassembled key based on the second image for authentication by disassembling the steganography algorithm; and

determining that authentication on the second image for authentication is failed in case that the disassembled key is not matched with the key.

14. The image authentication method of claim 13 , wherein said generating a disassembled key based on the second image for authentication by disassembling the steganography algorithm comprises:

determining a plurality of pixel positions in the second image for authentication based on the key;

reading pixel values at the plurality of pixel positions; and

generating the disassembled key based on the read pixel values.

15. The image authentication method of claim 13 , further comprising:

returning to the client that the authentication is failed in case that the authentication on the second image for authentication is failed.

16. The image authentication method of claim 13 , further comprising:

generating a session identification in response to the key acquiring request; and

associating and storing the key and the session identification after the key is generated.

17. The image authentication method of claim 13 , wherein the key is sent to the client through an encrypted channel and the second image for authentication is received from the client through the encrypted channel.

18. A client device, comprising:

an image collecting apparatus;

a communication apparatus;

one or more processors; and

one or more storage apparatuses with computer program instructions stored thereon, the computer program instructions, when being executed by the processor, cause the processor:

controlling the image collecting apparatus to photograph an object to obtain a first image;

controlling the communication apparatus to send a key acquiring request to a server and receive a key from the server;

generating a second image for authentication based on the key and the first image; and

controlling the communication apparatus to send the second image for authentication to the server,

wherein the key is generated in real time by the server in response to the key acquiring request and the key changes with time, and

wherein the server determines a time difference between a time at which the key is sent to the client device and a time at which the second image for authentication is received from the client device, and determines that the authentication is failed in case that the time difference exceeds a key expiration period.