Gesture-based CAPTCHA

captchaOverview
This project aims to develop a new CAPTCHA scheme (Completely Automated Public Turing test to tell Computers and Human Apart) with enhanced mobile user experience while retaining the necessary level of security. Unlike conventional text-recognition based CAPTCHA schemes and even the latest interactive CAPTCHA schemes, this proposed CAPTCHA scheme takes a hybrid approach to strike a balance between usability and security.

The scheme features an instructional layer which utilises cognitive psychology findings to form a CAPTCHA challenge which can be easily understood by human users but not by bots and an interaction layer which allows users to perform gesture friendly interactions to respond to the CAPTCHA challenge. A typical example is to partially process object moving challenge instructions to force a user to utilise context effect to understand the instruction and respond to it. Since computer bots cannot easily apply context effect to understand the instruction, they have to use brute force to try out all possible movements. Then the security can be retained by simply adding more success criteria to lower the probability of using brute force to crack the challenge.

Demo:

ContactsNan Jiang

Funders: Bournemouth University

Collaborators:

Related Publications

  • N. Jiang, H. Dogan, and F. Tian, “Designing Mobile Friendly CAPTCHAs: An Exploratory Study,” in Proceedings of the 31st British HCI Group Annual Conference on People and Computers: Digital Make Believe, 2017.
    [Bibtex]
    @inproceedings{jidt17,
    Author = {Nan Jiang and Huseyin Dogan and Feng Tian},
    Booktitle = {{Proceedings of the 31st British HCI Group Annual Conference on People and Computers: Digital Make Believe}},
    Note = {To Appear},
    Publisher = {British Computer Society},
    Title = {{Designing Mobile Friendly CAPTCHAs: An Exploratory Study}},
    Year = {2017}}
  • N. Jiang and F. Tian, “A novel gesture-based captcha design for smart devices,” in Proceedings of the 27th international bcs human computer interaction conference, 2013, p. 49:1–49:5.
    [Bibtex]
    @inproceedings{jiti13,
    Author = {Jiang, Nan and Tian, Feng},
    Booktitle = {Proceedings of the 27th International BCS Human Computer Interaction Conference},
    Pages = {49:1--49:5},
    Publisher = {British Computer Society},
    Series = {BCS-HCI '13},
    Title = {A Novel Gesture-based CAPTCHA Design for Smart Devices},
    Year = {2013}}
  • N. Jiang and H. Dogan, “A Gesture-based CAPTCHA Design Supporting Mobile Devices,” in Proceedings of the 2015 british hci conference, 2015, p. 202–207.
    [Bibtex]
    @inproceedings{jido15,
    Author = {Jiang, Nan and Dogan, Huseyin},
    Booktitle = {Proceedings of the 2015 British HCI Conference},
    Pages = {202--207},
    Publisher = {ACM},
    Series = {British HCI '15},
    Title = {{A Gesture-based CAPTCHA Design Supporting Mobile Devices}},
    Year = {2015}}