Picturesque

1,024 views
1,000 views

Published on

Mobile internet users are prompted to solve the same text-based CAPTCHAs used on desktop computers, but it has been found that mobile devices are poorly suited for solving these text-based CAPTCHA tests. These tests are more difficult on mobile devices because text is time-consuming to enter and the size of mobile displays can make the CAPTCHA hard to see and interpret. We introduce a new CAPTCHA mechanism called Picturesque specifically designed for mobile phone devices, based on image recognition techniques.

Published in: Technology, Design
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,024
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Picturesque

  1. 1. Picturesque<br />CAPTCHA for Mobile Devices<br />
  2. 2. Design Problem<br />CAPTCHAs are difficult to interpret<br />And they are difficult to type<br />
  3. 3. Design Problem<br />Mobile internet users are prompted to solve the same text-based CAPTCHAsused on desktop computers, but it has been found that mobile devices are poorly suited for solving these text-based CAPTCHA tests<br />
  4. 4. Solution<br />An image based CAPTCHA that does not require keyboard based input<br />
  5. 5. User Needs<br />“..should be easy to understand”<br />
  6. 6. User Needs<br />“..should be easy to understand”<br />“typing random words is painful using mobile phones, especially due to autocorrect; don’t ask me to type”<br />
  7. 7. Goals<br />Typing on mobile devices is hard, so no more keyboard based input<br />Design Goals<br />
  8. 8. Goals<br />Typing on mobile devices is hard, so no more keyboard based input<br />Design Goals<br />Should take less than a minute to solve<br />
  9. 9. Goals<br />Typing on mobile devices is hard, so no more keyboard based input<br />Design Goals<br />Must be highly secure to avoidany SPAM attack<br />Should take less than a minute to solve<br />
  10. 10. Contextual Inquiry & Sketches<br />We chose few representative tasks in which CAPTCHAs are generally encountered (for example user registration) and asked our test users to complete those tasks<br />
  11. 11. Contextual Inquiry & Sketches<br />We chose few representative tasks in which CAPTCHAs are generally encountered (for example user registration) and asked our test users to complete those tasks<br />As a result of contextual inquiry, we conducted a brainstorming session to sketchthree concepts for our design<br />
  12. 12. Paper Prototypes<br />Evaluated all the three sketches rigorously keeping in mind the design goals & user needs and as a result of evaluation one of the three concepts was chosen for paper prototypes<br />Design for our paper prototype consisted of two steps, first users had to identify images from specific category and then they had trace the outline of identified image<br />
  13. 13. Design Iteration<br />Based on the results from user studies, we realized image tracing is neither fast nor obvious<br />Choosing images is much more easier from user standpoint<br />
  14. 14. Interactive Prototype: Design<br />Two grids of 9 images in 3-by-3 format<br />
  15. 15. Interactive Prototype: Design<br />User is asked to select images from a specific category, such as Eiffel Tower, Lions, or Shoes<br />Two grids of 9 images in 3-by-3 format<br />
  16. 16. Interactive Prototype: Design<br />User is asked to select images from a specific category, such as Eiffel Tower, Lions, or Shoes<br />Two grids of 9 images in 3-by-3 format<br />User has to select images that are related to chosen category to pass the test<br />
  17. 17. User Studies<br />Extensive study with 61 subjects using Amazon Mechanical Turk<br />An in-person study with 6 users<br />Image: http://www.flickr.com/photos/leeander/4132537169/<br />
  18. 18. User Study Results<br />Both studies compared our Picturesque technique to reCAPTCHA, a common text-based CAPTCHA <br />Based on the results, we observed that time completion rate for a task of Picturesque was better than reCAPTCHAtask in most of the cases<br />
  19. 19. Picturesque: Final Design<br /># of images that needs to be selected in a grid is randomly chosen to be either 4 or 5<br />
  20. 20. Picturesque: Final Design<br /># of images that needs to be selected in a grid is randomly chosen to be either 4 or 5<br />Placement of the images is random<br />
  21. 21. Picturesque: Final Design<br /># of images that needs to be selected in a grid is randomly chosen to be either 4 or 5<br />Placement of the images is random<br />Two grids of nine images are necessary from security perspective<br />
  22. 22. Thank You!<br />Team Members: DhawalMujumdar | Alex Smolen | Becky Hurwitz<br />

×