Abstract
This chapter presents the most advanced algorithms which are used to successfully design a CAPTCHA test. In the first part, the most important techniques which are employed for designing a text CAPTCHA are described. In fact, although it is the most attacked type of CAPTCHA, it is still used in many web sites. Then, the attention will be moved toward the design of the image-based CAPTCHA, for which different techniques of image transformation are usually employed. The third part will be dedicated to algorithms and methods for designing other types of CAPTCHA, such as text-based reCAPTCHA, NoCAPTCHA reCAPTCHA, and game-based CAPTCHA. Finally, the last part of the chapter provides a practical mini-guide on how to design a simple text and image-based CAPTCHA in JavaScript and PHP.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Bursztein E, Martin M, Mitchell J (2011) Text-based CAPTCHA strengths and weaknesses. In: Proceeding of ACM conference on computer and communications security. ACM, New York, NY, USA, pp 125–138
BotDetect CAPTCHA Image Samples. https://captcha.com/captcha-examples.html
Basso A, Sicco S (2009) Preventing massive automated access to web resources. Comput Secur 28:174–188
Goswami G, Powell BM, Vatsa M, Singh R, Noore A (2014) FR-CAPTCHA: CAPTCHA based on recognizing human faces. PLoS ONE 9(4):e91708
Datta R, Li J, Wang JZ (2009) Exploiting the human-machine gap in image recognition for designing CAPTCHAs. IEEE Trans Inf Forensics Secur 4(3):504–518
Von Ahn L, Maurer B, Mcmillen C, Abraham D, Blum M (2008) reCAPTCHA: human-based character recognition via web security measures. Science 32:1465–1468
O’Reilly L (2015) Google’s new CAPTCHA security login raises ‘legitimate privacy concerns’. http://www.businessinsider.com/google-no-captcha-adtruth-privacy-research-2015-2?IR=T
Manoj TH, Basavaraj R, Jyoti (2016) Security enhancement in captcha recognition using animated GIF images. Int J Comput Appl 156(7):43–46
Gao S, Mohamed M, Saxena N, Zhang C (2014) Dynamic cognitive game CAPTCHA usability and detection of streaming-based farming. In: Workshop on usable security. USEC Proceedings, pp 1–10
JavaScript. https://www.w3schools.com/js/
jQuery. https://jquery.com
The Crazy Programmer (2012) JavaScript CAPTCHA example. http://www.thecrazyprogrammer.com/2016/03/javascript-captcha-example.html
Bux H (2014) How to create CAPTCHA image verification in PHP and jQuery. http://www.phpgang.com/how-to-create-captcha-image-verification-in-php-and-jquery_456.html
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Copyright information
© 2020 Springer Nature Switzerland AG
About this chapter
Cite this chapter
Brodić, D., Amelio, A. (2020). CAPTCHA Programming. In: The CAPTCHA: Perspectives and Challenges. Smart Innovation, Systems and Technologies, vol 162. Springer, Cham. https://doi.org/10.1007/978-3-030-29345-1_8
Download citation
DOI: https://doi.org/10.1007/978-3-030-29345-1_8
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-29344-4
Online ISBN: 978-3-030-29345-1
eBook Packages: Intelligent Technologies and RoboticsIntelligent Technologies and Robotics (R0)