EnSolver: Uncertainty-Aware Ensemble CAPTCHA Solvers with Theoretical Guarantees

arXiv:2307.15180v2 Announce Type: replace-cross
Abstract: The popularity of text-based CAPTCHA as a security mechanism to protect websites from automated bots has prompted researches in CAPTCHA solvers, with the aim of understanding its failure cases and subsequently making CAPTCHAs more secure. Recently proposed solvers, built on advances in deep learning, are able to crack even the very challenging CAPTCHAs with high accuracy. However, these solvers often perform poorly on out-of-distribution samples that contain visual features different from those in the training …

aim arxiv automated automated bots aware bots captcha captchas cases cs.cr cs.cv deep learning failure making mechanism protect security text uncertainty understanding websites