A security analysis of automated Chinese turing tests

Algwil, Abdalnaser and Ciresan, Dan and Liu, Beibei and Yan, Jeff (2016) A security analysis of automated Chinese turing tests. In: ACSAC '16 Proceedings of the 32nd Annual Conference on Computer Security Applications. ACM, New York, pp. 520-532. ISBN 9781450347716

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Text-based Captchas have been widely used to deter misuse of services on the Internet. However, many designs have been broken. It is intellectually interesting and practically relevant to look for alternative designs, which are currently a topic of active research. We motivate the study of Chinese Captchas as an interesting alternative design - counterintuitively, it is possible to design Chinese Captchas that are universally usable, even to those who have never studied Chinese language. More importantly, we ask a fundamental question: is the segmentation-resistance principle established for Roman-character based Captchas applicable to Chinese based designs? With deep learning techniques, we offer the first evidence that computers do recognize individual Chinese characters well, regardless of distortion levels. This suggests that many real-world Chinese schemes are insecure, in contrast to common beliefs. Our result offers an essential guideline to the design of secure Chinese Captchas, and it is also applicable to Captchas using other large-alphabet languages such as Japanese.

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17 Nov 2016 11:00
Last Modified:
16 Sep 2023 03:10