STE3D-CAP: Stereoscopic 3D CAPTCHA Willy Susilo, Yang-Wai Chow and - PowerPoint PPT Presentation

STE3D-CAP: Stereoscopic 3D CAPTCHA Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Outline Background and Motivation Existing Work Our Contributions CAPTCHA: Formal Definition STE3D-CAP: Design and Implementation Security Considerations Applications Conclusion Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Background and Motivation CAPTCHAs: simple problems that can be quickly solved by humans, but are difficult for computers to solve. Hundreds of designs have been put forth after von Ahn et al.’s seminal work in Eurocrypt 2003. CAPTCHAs are used to prevent exploitations by bots and automated scripts in public web services, which are rapidly increasing. Using CAPTCHAs, services can distinguish legitimate users from computer bots while requiring minimal effort by the human user. Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Different types of CATPCHA To date, there exist three main types of CAPTCHAs: Text-based CAPTCHAs: typically obtained by selecting a sequence of letters, rendering them, distorting the image and adding some noise; Image-based CAPTCHAs: typically ask users to conduct an image recognition task; and Sound-based CAPTCHAs (or audio CAPTCHAs): typically require users to solve a speech recognition task. Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Existing Work GIMPY and EZ-GIMPY CAPTCHA Google CAPTCHA Microsoft CAPTCHA Yahoo CAPTCHA vulnerable against attacks, such as pattern recognition, Optical Character Recognitions (OCR) or segmentation techniques. Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Existing Work Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Existing Work Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Our Contributions Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Our Contributions We present a text-based CAPTCHA that is built from stereoscopic 3D images, STE3D-CAP . STE3D-CAP is easy for human users, as it can be solved by humans who are equipped with an “appropriate" 3D visualization device (eg. Stereoscopic 3D display and glasses). Main drawback: it relies on the required stereoscopic display hardware that the user must own. Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

STE3D-CAP Humans can solve it quickly. Computers cannot solve it easily. STE3D-CAP is easy to generate as it is a text-based CAPTCHA. STE3D-CAP uses the latest technology. STE3D-CAP uses 3D, and hence, more noise can be added in the 3D scene while the resulting CAPTCHA is still usable. STE3D-CAP is a variable length CAPTCHA, which are more difficult to defeat. STE3D-CAP is built in a 3D environment, and therefore more distortion can be added to the CAPTCHA (eg. negative/positive parallax). Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

STE3D-CAP: Problem Family Problem Family ( P STE 3 D − CAP ) Consider the following experiment. Randomly select i ∈ |I 3 d | . 1 Compute i ← ∆( i ) . 2 Select a transformation t ← T . 3 Compute ¯ i ← t ( i ) . 4 Select a clutter function c ← C . 5 Compute j ← c (¯ i , ω, υ ) , where ω ∈ Ω and υ ∈ Υ are 6 selected randomly. Output ϑ − 1 ( j ) . 7 The output of the experiment is ( j L , j R ) ← ϑ − 1 ( j ) , where ( j L , j R ) ∈ I 2 d × I 2 d . Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Hard Problem in P STE 3 D − CAP We believe that P STE 3 D − CAP contains a hard problem. Given P STE 3 D − CAP = ( S I 2 d , T , C , D I 2 d , T , C , f I 2 d , T , C ) , for any program B , Pr x ← D I 2 d , T , C , r [ B r ( x ) = f ( x )] < η. Based on this hard problem, we can construct a secure ( α, β, η ) -CAPTCHA. Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

STE3D-CAP Theorem 1. A secure ( α, β, η ) -CAPTCHA can be constructed from P STE3D-CAP as defined above. Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Security Considerations Single Image Attacks - Edge Detection Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Security Considerations 2D Image Difference Attacks Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Security Considerations Other attacks: Brute Force Attacks 3D Reconstruction Attacks Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Applications 3D Massively Multiplayer Online Games (MMOGs). low-cost anaglyph approach as a drop-in replacement for current CAPTCHAs on web pages. Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA

Conclusions We presented STE3D-CAP that attempts to overcome limitations with existing 2D approaches. We demonstrated that STE3D-CAP is resistant against the existing 2D CAPTCHA attacks. Our approach has opened a new research direction to incorporate CAPTCHA challenges in 3D scenes. Willy Susilo, Yang-Wai Chow and Hua-Yu Zhou University of Wollongong, Australia {wsusilo, caseyc, hz285}@uow.edu.au STE3D-CAP: Stereoscopic 3D CAPTCHA