We introduce a new type of 3D text-based CAPTCHA, called DotCHA, which relies on human interaction. DotCHA asks users to rotate a 3D text model to identify the correct letters. The 3D text model is a twisted form of sequential 3D letters around a center pivot axis, and it shows different letters depending on the rotation angle. The model is not composed of a solid letter model, but a number of spheres to resist character segmentation attacks, and this is why DotCHA is classified as a scatter-type CAPTCHA. Since each letter can only be identified in a particular direction, it makes DotCHA resistant to machine learning attacks. We demonstrate that DotCHA, while maintaining usability, is resistant to existing types of attacks.
Suzi Kim and Sunghee Choi
@ Geomtric Computing Lab., School of Computing, KAIST
presented at ICWE 2019
(Distinguished Paper Award)
- Kim S., & Choi S. (2019) DotCHA: A 3D Text-Based Scatter-Type CAPTCHA. In: Bakaev M., Frasincar F., Ko IY. (eds) Web Engineering. ICWE 2019. Lecture Notes in Computer Science, vol 11496. Springer, Cham
@inproceedings{Kim2019DotCHA,
author = {Suzi Kim and
Sunghee Choi},
title = {DotCHA: {A} 3D Text-Based Scatter-Type {CAPTCHA}},
booktitle = {Web Engineering - 19th International Conference, {ICWE} 2019, Daejeon,
South Korea, June 11-14, 2019, Proceedings},
pages = {238--252},
year = {2019},
crossref = {DBLP:conf/icwe/2019},
url = {https://doi.org/10.1007/978-3-030-19274-7\_18},
doi = {10.1007/978-3-030-19274-7\_18},
}
- Kim S., & Choi S. (2020) DotCHA: An Interactive 3D Text-based CAPTCHA. Journal of Web Engineering, 18(8), 837–864, doi:10.13052/jwe1540-9589.1884
@article{Kim2020DotCHA,
author = {Suzi Kim and
Sunghee Choi},
title = {DotCHA: {An} Interactive 3D Text-based {CAPTCHA}},
journal = {Journal of Web Engineering},
year = {2020},
month = jan,
volume = {18},
number = {8},
pages = {837--864},
issn = {1540-9589},
url = {https://doi.org/10.13052/jwe1540-9589.1884},
doi = {10.13052/jwe1540-9589.1884},
}