CAPTCHA image scramble

1. A method comprising: by a first computing device,

accessing a first image of a CAPTCHA, wherein the CAPTCHA comprises:

the first image;

a challenge based on the first image; and

a correct response based on the first image;

constructing a second image by scrambling the first image, comprising:

cutting the first image into a plurality of image sections;

recording positions of the image sections in the first image; and

randomly rearranging the image sections to construct the second image;

generating web-browser-executable code for unscrambling the second image back to the first image, wherein the web-browser-executable code indicates, for each one of the image sections in the second image, the position of the image section in the first image; and

transmitting the second image and the web-browser-executable code to a second computing device.

2. The method recited in claim 1 , wherein the web-browser-executable code includes Cascading Style Sheets (CSS) code.

3. The method recited in claim 1 , wherein the first image is never transmitted to the second computing device.

4. The method recited in claim 1 , wherein the first image and the second image have a same dimension.

5. The method recited in claim 1 , wherein the first image is cut horizontally or vertically or both horizontally and vertically.

6. The method recited in claim 1 , further comprising:

constructing Hyper Text Markup Language (HTML) code that lists each one of the image sections in the second image; and

transmitting the HTML code to the second computing device.

7. The method recited in claim 1 , further comprising transmitting the challenge to the second computing device.

8. A method comprising: by a second computing device,

receiving a second image and web-browser-executable code from a first computing device, wherein:

the second image is constructed by randomly rearranging a plurality of image sections of a first image of a CAPTCHA;

the CAPTCHA comprises the first image, a challenge based on the first image; and a correct response based on the first image; and

the web-browser-executable code indicates, for each one of the image sections in the second image, a position of the image section in the first image; and

displaying the first image based on the second image and the web-browser-executable code.

9. The method recited in claim 8 , wherein the web-browser-executable code includes Cascading Style Sheets (CSS) code.

10. The method recited in claim 8 , further comprising:

receiving the challenge from the first computing device; and

displaying the challenge with the first image.

11. The method recited in claim 10 , further comprising:

receiving a response to the challenge from a human user of the second computing device; and

transmitting the response to the first computing device in response to the CAPTCHA.

12. A first computing device comprising:

a memory comprising instructions executable by one or more processors; and

one or more processors coupled to the memory and operable to execute the instructions, the one or more processors being operable when executing the instructions to:

access a first image of a CAPTCHA, wherein the CAPTCHA comprises:

the first image;

a challenge based on the first image; and

a correct response based on the first image;

construct a second image by scrambling the first image, comprising:

cut the first image into a plurality of image sections;

record positions of the image sections in the first image; and

randomly rearrange the image sections to construct the second image;

generate web-browser-executable code for unscrambling the second image back to the first image, wherein the web-browser-executable code indicates, for each one of the image sections in the second image, the position of the image section in the first image; and

transmit the second image and the web-browser-executable code to a second computing device.

13. The first computing device recited in claim 12 , wherein the web-browser-executable code includes Cascading Style Sheets (CSS) code.

14. The first computing device recited in claim 12 , wherein the first image is never transmitted to the second computing device.

15. The first computing device recited in claim 12 , wherein the first image and the second image have a same dimension.

16. The first computing device recited in claim 12 , wherein the first image is cut horizontally or vertically or both horizontally and vertically.

17. The first computing device recited in claim 12 , wherein the one or more processors are further operable when executing the instructions to:

construct Hyper Text Markup Language (HTML) code that lists each one of the image sections in the second image; and

transmit the HTML code to the second computing device.

18. The first computing device recited in claim 12 , wherein the one or more processors are further operable when executing the instructions to transmit the challenge to the second computing device.

19. A second computing device comprising:

a memory comprising instructions executable by one or more processors; and

one or more processors coupled to the memory and operable to execute the instructions, the one or more processors being operable when executing the instructions to:

receive a second image and web-browser-executable code from a first computing device, wherein:

the second image is constructed by randomly rearranging a plurality of image sections of a first image of a CAPTCHA;

the CAPTCHA comprises the first image, a challenge based on the first image; and a correct response based on the first image; and

the web-browser-executable code indicates, for each one of the image sections in the second image, a position of the image section in the first image; and

display the first image based on the second image and the web-browser-executable code.

20. The second computing device recited in claim 19 , wherein the web-browser-executable code includes Cascading Style Sheets (CSS) code.

21. The second computing device recited in claim 19 , wherein the one or more processors are further operable when executing the instructions to:

receive the challenge from the first computing device; and

display the challenge with the first image.

22. The second computing device recited in claim 21 , wherein the one or more processors are further operable when executing the instructions to:

receive a response to the challenge from a human user of the second computing device; and

transmit the response to the first computing device in response to the CAPTCHA.

23. One or more computer-readable tangible storage media embodying software operable when executed by a first computing device to:

access a first image of a CAPTCHA, wherein the CAPTCHA comprises:

the first image;

a challenge based on the first image; and

a correct response based on the first image;

construct a second image by scrambling the first image, comprising:

cut the first image into a plurality of image sections;

record positions of the image sections in the first image; and

randomly rearrange the image sections to construct the second image;

generate web-browser-executable code for unscrambling the second image back to the first image, wherein the web-browser-executable code indicates, for each one of the image sections in the second image, the position of the image section in the first image; and

transmit the second image and the web-browser-executable code to a second computing device.

24. The media recited in claim 23 , wherein the web-browser-executable code includes Cascading Style Sheets (CSS) code.

25. The media recited in claim 23 , wherein the first image is never transmitted to the second computing device.

26. The media recited in claim 23 , wherein the first image and the second image have a same dimension.

27. The media recited in claim 23 , wherein the first image is cut horizontally or vertically or both horizontally and vertically.

28. The media recited in claim 23 , wherein the software is further operable when executed by the first computing device to:

construct Hyper Text Markup Language (HTML) code that lists each one of the image sections in the second image; and

transmit the HTML code to the second computing device.

29. The media recited in claim 23 , wherein the software is further operable when executed by the first computing device to transmit the challenge to the second computing device.

30. One or more computer-readable tangible storage media embodying software operable when executed by a second computing device to:

receive a second image and web-browser-executable code from a first computing device, wherein:

the second image is constructed by randomly rearranging a plurality of image sections of a first image of a CAPTCHA;

the CAPTCHA comprises the first image, a challenge based on the first image; and a correct response based on the first image; and

the web-browser-executable code indicates, for each one of the image sections in the second image, a position of the image section in the first image; and

display the first image based on the second image and the web-browser-executable code.

31. The media recited in claim 30 , wherein the web-browser-executable code includes Cascading Style Sheets (CSS) code.

32. The media recited in claim 30 , wherein the software is further operable when executed by the second computing device to:

receive the challenge from the first computing device; and

display the challenge with the first image.

33. The media recited in claim 32 , wherein the software is further operable when executed by the second computing device to:

receive a response to the challenge from a human user of the second computing device; and

transmit the response to the first computing device in response to the CAPTCHA.