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Related papers: User Friendly Line CAPTCHAs

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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

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

We introduce the novel approach towards fake text reviews detection in collaborative filtering recommender systems. The existing algorithms concentrate on detecting the fake reviews, generated by language models and ignore the texts,…

Artificial Intelligence · Computer Science 2023-01-10 Yuliya Tukmacheva , Ivan Oseledets , Evgeny Frolov

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

For a number of years, many websites have used CAPTCHAs to filter out interactions by bots. However, attackers have found ways to circumvent CAPTCHAs by programming bots to solve or bypass them, or even relay them for humans to solve. In…

Cryptography and Security · Computer Science 2017-04-11 Nasser Mohammed Al-Fannah

In contrast to software reverse engineering, there are hardly any tools available that support hardware reversing. Therefore, the reversing process is conducted by human analysts combining several complex semi-automated steps. However,…

Cryptography and Security · Computer Science 2019-10-02 Carina Wiesen , Nils Albartus , Max Hoffmann , Steffen Becker , Sebastian Wallat , Marc Fyrbiak , Nikol Rummel , Christof Paar

For nearly two decades, CAPTCHAs have been widely used as a means of protection against bots. Throughout the years, as their use grew, techniques to defeat or bypass CAPTCHAs have continued to improve. Meanwhile, CAPTCHAs have also evolved…

Cryptography and Security · Computer Science 2023-07-25 Andrew Searles , Yoshimichi Nakatsuka , Ercan Ozturk , Andrew Paverd , Gene Tsudik , Ai Enkoji

CAPTCHAs remain a critical defense against automated abuse, yet modern systems suffer from well-known limitations in usability, accessibility, and resistance to increasingly capable bots and low-cost CAPTCHA farms. Behavioral and…

Cryptography and Security · Computer Science 2026-03-09 Shovon Paul , Md Imran Hossen , Xiali Hei

The paper analyzes the interaction between humans and computers in terms of response time in solving the image-based CAPTCHA. In particular, the analysis focuses on the attitude of the different Internet users in easily solving four…

Human-Computer Interaction · Computer Science 2016-12-07 Darko Brodić , Alessia Amelio

Convolutional Neural Networks (CNNs) are deployed in more and more classification systems, but adversarial samples can be maliciously crafted to trick them, and are becoming a real threat. There have been various proposals to improve CNNs'…

Machine Learning · Computer Science 2020-02-21 Ilia Shumailov , Yiren Zhao , Robert Mullins , Ross Anderson

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…

To mitigate dictionary attacks or similar undesirable automated attacks to information systems, developers mostly prefer using CAPTCHA challenges as Human Interactive Proofs (HIPs) to distinguish between human users and scripts. Appropriate…

Cryptography and Security · Computer Science 2023-12-01 Emre Mulazimoglu , Murat P. Cakir , Cengiz Acarturk

Reverse engineering is a complex process essential to software-security tasks such as vulnerability discovery and malware analysis. Significant research and engineering effort has gone into developing tools to support reverse engineers.…

Cryptography and Security · Computer Science 2019-12-03 Daniel Votipka , Seth M. Rabin , Kristopher Micinski , Jeffrey S. Foster , Michelle L. Mazurek

Adversarial images are samples that are intentionally modified to deceive machine learning systems. They are widely used in applications such as CAPTHAs to help distinguish legitimate human users from bots. However, the noise introduced…

Computer Vision and Pattern Recognition · Computer Science 2019-05-13 Bilgin Aksoy , Alptekin Temizel

Attackers create adversarial text to deceive both human perception and the current AI systems to perform malicious purposes such as spam product reviews and fake political posts. We investigate the difference between the adversarial and the…

Computation and Language · Computer Science 2019-12-20 Hoang-Quoc Nguyen-Son , Tran Phuong Thao , Seira Hidano , Shinsaku Kiyomoto

Since about 2003, captchas have been widely used as a barrier against bots, while simultaneously annoying great multitudes of users worldwide. As their use grew, techniques to defeat or bypass captchas kept improving, while captchas…

Cryptography and Security · Computer Science 2023-11-23 Andrew Searles , Renascence Tarafder Prapty , Gene Tsudik

Recent work in automatic recognition of conversational telephone speech (CTS) has achieved accuracy levels comparable to human transcribers, although there is some debate how to precisely quantify human performance on this task, using the…

Computation and Language · Computer Science 2022-02-22 Andreas Stolcke , Jasha Droppo

In his seminal paper ``Computing Machinery and Intelligence'', Alan Turing introduced the ``imitation game'' as part of exploring the concept of machine intelligence. The Turing Test has since been the subject of much analysis, debate,…

Artificial Intelligence · Computer Science 2023-08-03 David Harel , Assaf Marron

The growing capability of large language models to produce fluent, contextually coherent text has created mounting pressure on the systems and institutions responsible for ensuring the authenticity of digital content. Advanced generative…

In this paper the elements of the CAPTCHA usability are analyzed. CAPTCHA, as a time progressive element in computer science, has been under constant interest of ordinary, professional as well as the scientific users of the Internet. The…

Human-Computer Interaction · Computer Science 2017-07-03 Darko Brodić , Alessia Amelio , Ivo R. Draganov