IMAGINATION: A Robust Image-based CAPTCHA Generation System

Ritendra Datta, Jia Li, James Z. Wang
The Pennsylvania State University, University Park, PA 16802

We propose IMAGINATION (IMAge Generation for INternet AuthenticaTION), a system for the generation of attack-resistant, user-friendly, image-based CAPTCHAs. In our system, we produce controlled distortions on randomly chosen images and present them to the user for annotation from a given list of words. The distortions are performed in a way that satisfies the incongruous requirements of low perceptual degradation and high resistance to attack by content-based image retrieval systems. Word choices are carefully generated to avoid ambiguity as well as to avoid attacks based on the choices themselves. Preliminary results demonstrate the attack-resistance and user-friendliness of our system compared to text-based CAPTCHAs.

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Citation: Ritendra Datta, Jia Li and James Z. Wang, ``IMAGINATION: A Robust Image-based CAPTCHA Generation System,'' Proceedings of the ACM Multimedia Conference, pp. 331-334, Singapore, ACM, November 2005.

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Last Modified: Wed Nov 2 11:38:12 EST 2005