Reliable Image-Text Fusion CAPTCHA to Improve User-Friendliness and Efficiency


The KIPS Transactions:PartC, Vol. 17, No. 1, pp. 27-36, Feb. 2010
10.3745/KIPSTC.2010.17.1.27,   PDF Download:

Abstract

In Web registration pages and online polling applications, CAPTCHA(Completely Automated Public Turing Test To Tell Computers and Human Apart) is used for distinguishing human users from automated programs. Text-based CAPTCHAs have been widely used in many popular Web sites in which distorted text is used. However, because the advanced optical character recognition techniques can recognize the distorted texts, the reliability becomes low. Image-based CAPTCHAs have been proposed to improve the reliability of the text-based CAPTCHAs. However, these systems also are known as having some drawbacks. First, some image-based CAPTCHA systems with small number of image files in their image dictionary is not so reliable since attacker can recognize images by repeated executions of machine learning programs. Second, users may feel uncomfortable since they have to try CAPTCHA tests repeatedly when they fail to input a correct keyword. Third, some image-base CAPTCHAs require high communication cost since they should send several image files for one CAPTCHA. To solve these problems of image-based CAPTCHA, this paper proposes a new CAPTCHA based on both image and text. In this system, an image and keywords are integrated into one CAPTCHA image to give user a hint for the answer keyword. The proposed CAPTCHA can help users to input easily the answer keyword with the hint in the fused image. Also, the proposed system can reduce the communication costs since it uses only a fused image file for one CAPTCHA. To improve the reliability of the image-text fusion CAPTCHA, we also propose a dynamic building method of large image dictionary from gathering huge amount of images from theinternet with filtering phase for preserving the correctness of CAPTCHA images. In this paper, we proved that the proposed image-text fusion CAPTCHA provides users more convenience and high reliability than the image-based CAPTCHA through experiments.


Statistics
Show / Hide Statistics

Statistics (Cumulative Counts from September 1st, 2017)
Multiple requests among the same browser session are counted as one view.
If you mouse over a chart, the values of data points will be shown.


Cite this article
[IEEE Style]
K. H. Moon and Y. S. Kim, "Reliable Image-Text Fusion CAPTCHA to Improve User-Friendliness and Efficiency," The KIPS Transactions:PartC, vol. 17, no. 1, pp. 27-36, 2010. DOI: 10.3745/KIPSTC.2010.17.1.27.

[ACM Style]
Kwang Ho Moon and Yoo Sung Kim. 2010. Reliable Image-Text Fusion CAPTCHA to Improve User-Friendliness and Efficiency. The KIPS Transactions:PartC, 17, 1, (2010), 27-36. DOI: 10.3745/KIPSTC.2010.17.1.27.