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Related papers: An Empirical Study & Evaluation of Modern CAPTCHAs

200 papers

Driven by ongoing improvements in machine learning, chatbots have increasingly grown from experimental interface prototypes to reliable and robust tools for process automation. Building on these advances, companies have identified various…

Human-Computer Interaction · Computer Science 2023-02-02 Alessandro Casadei , Stephan Schlögl , Markus Bergmann

A CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) is an automatic security mechanism used to determine whether the user is a human or a malicious computer program. It is a program that generates and…

Human-Computer Interaction · Computer Science 2013-12-31 Mohammad Jabed Morshed Chowdhury , Narayan Ranjan Chakraborty

CAPTCHAs are a defense mechanism to prevent malicious bot programs from abusing websites on the Internet. hCaptcha is a relatively new but emerging image CAPTCHA service. This paper presents an automated system that can break hCaptcha…

Cryptography and Security · Computer Science 2022-03-08 Md Imran Hossen , Xiali Hei

For the last ten years, CAPTCHAs have been widely used by websites to prevent their data being automatically updated by machines. By supposedly allowing only humans to do so, CAPTCHAs take advantage of the reverse Turing test (TT), knowing…

Computer Vision and Pattern Recognition · Computer Science 2014-09-04 Ahmad B. A. Hassanat

Online services rely on CAPTCHAs as a first line of defense against automated abuse, yet recent advances in multi-modal large language models (MLLMs) have eroded the effectiveness of conventional designs that focus on text recognition or 2D…

Artificial Intelligence · Computer Science 2025-10-07 Arina Kharlamova , Bowei He , Chen Ma , Xue Liu

It is increasingly becoming difficult for human beings to work on their day to day life without going through the process of reverse Turing test, where the Computers tests the users to be humans or not. Almost every website and service…

Computer Vision and Pattern Recognition · Computer Science 2020-06-23 Jimut Bahan Pal

Existing captcha solutions on the Internet are a major source of user frustration. Game captchas are an interesting and, to date, little-studied approach claiming to make captcha solving a fun activity for the users. One broad form of such…

Preventing abuse of web services by bots is an increasingly important problem, as abusive activities grow in both volume and variety. CAPTCHAs are the most common way for thwarting bot activities. However, they are often ineffective against…

Cryptography and Security · Computer Science 2020-07-22 Yoshimichi Nakatsuka , Ercan Ozturk , Andrew Paverd , Gene Tsudik

CAPTCHAs are widely deployed as human verification mechanisms and frequently block intelligent agents from completing end-to-end automation in real-world web environments. Solving modern CAPTCHAs requires robust multi-step visual reasoning…

Computer Vision and Pattern Recognition · Computer Science 2026-05-20 Pengcheng Wang , Haoxiang Liu , Yang Dai , Xiangxiang Zeng , Guanhua Chen , Baotian Hu , Longyue Wang , Weihua Luo

Bots constitute a significant portion of Internet traffic and are a source of various issues across multiple domains. Modern bots often become indistinguishable from real users, as they employ similar methods to browse the web, including…

Machine Learning · Computer Science 2024-12-04 Jan Kadel , August See , Ritwik Sinha , Mathias Fischer

Modern CAPTCHAs rely heavily on vision tasks that are supposedly hard for computers but easy for humans. However, advances in image recognition models pose a significant threat to such CAPTCHAs. These models can easily be fooled by…

Computer Vision and Pattern Recognition · Computer Science 2024-09-10 Yahya Jabary , Andreas Plesner , Turlan Kuzhagaliyev , Roger Wattenhofer

CAPTCHA(Completely Automated Public Turing test to Tell Computers and Humans Apart) can be used to protect data from auto bots. Countless kinds of CAPTCHAs are thus designed, while we most frequently utilize text-based scheme because of…

Computer Vision and Pattern Recognition · Computer Science 2018-06-20 Ye Wang , Mi Lu

As automation bot technology and Artificial Intelligence is evolving rapidly, conventional human verification techniques like voice CAPTCHAs and knowledge-based authentication are becoming less effective. Bots and scrapers with Artificial…

Cryptography and Security · Computer Science 2025-11-12 Aditya Mitra , Sibi Chakkaravarthy Sethuraman , Devi Priya V S

With the growth of connectivity to smart grids, new applications, and the changing interaction between customer and energy clouds, clouds are more vulnerable to denial-of-service attacks. Efficient detection methods are required to…

Cryptography and Security · Computer Science 2020-04-10 Monther Aldwairi , Suaad Mohammed , Megana Lakshmi Padmanabhan

Audio CAPTCHAs are supposed to provide a strong defense for online resources; however, advances in speech-to-text mechanisms have rendered these defenses ineffective. Audio CAPTCHAs cannot simply be abandoned, as they are specifically named…

As multimodal large language models (LLMs) advance, traditional CAPTCHAs have become obsolete at distinguishing humans from bots. To address this shift, this paper aims to investigate the possibility of using tasks for which humans have…

Cryptography and Security · Computer Science 2026-04-07 Choon-Hou Rafael Chong

CAPTCHAs or reverse Turing tests are real-time assessments used by programs (or computers) to tell humans and machines apart. This is achieved by assigning and assessing hard AI problems that could only be solved easily by human but not by…

Human-Computer Interaction · Computer Science 2014-02-05 A. K. B. Karunathilake , B. M. D. Balasuriya , R. G. Ragel

The rapid evolution of GUI-enabled agents has rendered traditional CAPTCHAs obsolete. While previous benchmarks like OpenCaptchaWorld established a baseline for evaluating multimodal agents, recent advancements in reasoning-heavy models,…

Machine Learning · Computer Science 2026-02-10 Jiacheng Liu , Yaxin Luo , Jiacheng Cui , Xinyi Shang , Xiaohan Zhao , Zhiqiang Shen

Deep learning technology has made it possible to generate realistic content of specific individuals. These `deepfakes' can now be generated in real-time which enables attackers to impersonate people over audio and video calls. Moreover,…

Cryptography and Security · Computer Science 2023-01-10 Lior Yasur , Guy Frankovits , Fred M. Grabovski , Yisroel Mirsky

While Artificial Intelligence has successfully outperformed humans in complex combinatorial games (such as chess and checkers), humans have retained their supremacy in social interactions that require intuition and adaptation, such as…

Computers and Society · Computer Science 2014-04-22 Fatimah Ishowo-Oloko , Jacob Crandall , Manuel Cebrian , Sherief Abdallah , Iyad Rahwan