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On the security of text-based 3D CAPTCHAs

Journal Article


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Abstract


  • CAPTCHAs have become a standard security mechanism that are used to deter automated

    abuse of online services intended for humans. However, many existing CAPTCHA schemes

    to date have been successfully broken. As such, a number of CAPTCHA developers have

    explored alternative methods of designing CAPTCHAs. 3D CAPTCHAs is a design alternative

    that has been proposed to overcome the limitations of traditional CAPTCHAs. These

    CAPTCHAs are designed to capitalize on the human visual system's natural ability to

    perceive 3D objects from an image. The underlying security assumption is that it is difficult

    for a computer program to identify the 3D content. This paper investigates the robustness

    of text-based 3D CAPTCHAs. In particular, we examine three existing text-based 3D

    CAPTCHA schemes that are currently deployed on a number of websites. While the direct

    use of Optical Character Recognition (OCR) software is unable to correctly solve these textbased

    3D CAPTCHA challenges, we highlight certain patterns in the 3D CAPTCHAs can be

    exploited to identify important information within the CAPTCHA. By extracting this information,

    this paper demonstrates that automated attacks can be used to solve these 3D

    CAPTCHAs with a high degree of success.

Publication Date


  • 2014

Citation


  • Nguyen, V., Chow, Y. & Susilo, W. (2014). On the security of text-based 3D CAPTCHAs. Computers and Security, 45 (September), 84-99.

Scopus Eid


  • 2-s2.0-84903143526

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=4088&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/3072

Number Of Pages


  • 15

Start Page


  • 84

End Page


  • 99

Volume


  • 45

Issue


  • September

Abstract


  • CAPTCHAs have become a standard security mechanism that are used to deter automated

    abuse of online services intended for humans. However, many existing CAPTCHA schemes

    to date have been successfully broken. As such, a number of CAPTCHA developers have

    explored alternative methods of designing CAPTCHAs. 3D CAPTCHAs is a design alternative

    that has been proposed to overcome the limitations of traditional CAPTCHAs. These

    CAPTCHAs are designed to capitalize on the human visual system's natural ability to

    perceive 3D objects from an image. The underlying security assumption is that it is difficult

    for a computer program to identify the 3D content. This paper investigates the robustness

    of text-based 3D CAPTCHAs. In particular, we examine three existing text-based 3D

    CAPTCHA schemes that are currently deployed on a number of websites. While the direct

    use of Optical Character Recognition (OCR) software is unable to correctly solve these textbased

    3D CAPTCHA challenges, we highlight certain patterns in the 3D CAPTCHAs can be

    exploited to identify important information within the CAPTCHA. By extracting this information,

    this paper demonstrates that automated attacks can be used to solve these 3D

    CAPTCHAs with a high degree of success.

Publication Date


  • 2014

Citation


  • Nguyen, V., Chow, Y. & Susilo, W. (2014). On the security of text-based 3D CAPTCHAs. Computers and Security, 45 (September), 84-99.

Scopus Eid


  • 2-s2.0-84903143526

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=4088&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/3072

Number Of Pages


  • 15

Start Page


  • 84

End Page


  • 99

Volume


  • 45

Issue


  • September