A systematic survey on CAPTCHA recognition: types, creation and breaking techniques

M Kumar, MK **dal, M Kumar - Archives of Computational Methods in …, 2022 - Springer
CAPTCHA stands for Completely Automated Public Turing Test to Tell Computers and
Human Apart. CAPTCHA is used for internet security. A few CAPTCHA schemes are …

An efficient technique for breaking of coloured Hindi CAPTCHA

M Kumar, MK **dal, M Kumar - Soft Computing, 2023 - Springer
Cyber-attacks on the internet are not a new phenomenon. Hackers are always looking for
ways to breach the security of the internet. Good researchers continuously develop solutions …

CAPTCHA design and security issues

YW Chow, W Susilo, P Thorncharoensri - Advances in Cyber Security …, 2019 - Springer
The concept of reverse Turing tests, or more commonly known as CAPTCHAs, for
distinguishing between humans and computers has been around for many years. The …

Semi-supervised deep learning approach to break common CAPTCHAs

O Bostik, K Horak, L Kratochvila, T Zemcik… - Neural Computing and …, 2021 - Springer
Manual data annotation is a time consuming activity. A novel strategy for automatic training
of the CAPTCHA breaking system with no manual dataset creation is presented in this …

Breaking an animated CAPTCHA scheme

VD Nguyen, YW Chow, W Susilo - … , ACNS 2012, Singapore, June 26-29 …, 2012 - Springer
CAPTCHAs have become a ubiquitous security countermeasure to protect online web-
services against automated attacks. However, attackers have managed to successfully …

A Survey of Adversarial CAPTCHAs on its History, Classification and Generation

Z Xu, Q Yan, FR Yu, V Leung - arxiv preprint arxiv:2311.13233, 2023 - arxiv.org
Completely Automated Public Turing test to tell Computers and Humans Apart, short for
CAPTCHA, is an essential and relatively easy way to defend against malicious attacks …

Dotcha: A 3d text-based scatter-type captcha

S Kim, S Choi - Web Engineering: 19th International Conference, ICWE …, 2019 - Springer
We introduce a new type of 3D text-based CAPTCHA, called DotCHA, which relies on
human interaction. DotCHA asks users to rotate a 3D text model to identify the correct letters …

A CAPTCHA scheme based on the identification of character locations

VD Nguyen, YW Chow, W Susilo - … , ISPEC 2014, Fuzhou, China, May 5-8 …, 2014 - Springer
CAPTCHAs are a standard security mechanism used on many websites to protect online
services against abuse by automated programs, or bots. The purpose of a CAPTCHA is to …

A challenge-response mechanism for securing online social networks against social bots

T Mohamed, M Ali, I Hani - International Journal of Ad Hoc …, 2019 - inderscienceonline.com
Social bots is fast becoming a serious security threat to online social networks (OSNs).
Social bots are automated software tools able to execute malicious activities in OSNs …

Directcha: A proposal of spatiometric mental rotation CAPTCHA

A Sano, M Fujita, M Nishigaki - 2016 14th Annual Conference …, 2016 - ieeexplore.ieee.org
A 3D CAPTCHA using mental rotation, called YUNiTi CAPTCHA, has been proposed as an
advanced system to enable discrimination between computers and humans. YUNiTi …