University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Captchæcker: Reconfigurable CAPTCHAs Based on Automated Security and Usability Analysis

Javed, Y, Nazir, M, Khan, MM, Khayam, SA and Li, SJ (2012) Captchæcker: Reconfigurable CAPTCHAs Based on Automated Security and Usability Analysis In: 4th Symposium on Configuration Analytics and Automation (SafeConfig 2011), 2011-10-31 - 2011-11-01, Arlington, VA, USA.

Available under License : See the attached licence file.

Download (247kB)
Text (licence)

Download (33kB)


CAPTCHAs have been deployed ubiquitously by web sites to combat automated malicious programs. Security against web bots and usability to legitimate users are two main goals that have to be simultaneously satisfied when designing a useful CAPTCHA scheme. However, there exists a well-known and intricate trade-off between these goals. So far, balancing this trade-off remains an art rather than a science, as we do not have any automated tools to evaluate the security and usability of CAPTCHAs and then to configure the CAPTCHA generation engine accordingly. In this position paper, we propose a general framework called Captchæcker that aims to solve this configuration problem by automating the security-usability analysis of CAPTCHAs. The proposed framework will allow dynamic reconfiguration of a CAPTCHA scheme after its securityusability goal is changed or its security is compromised due to an attack.

Item Type: Conference or Workshop Item (Conference Paper)
Divisions : Faculty of Engineering and Physical Sciences > Computing Science
Authors :
Javed, Y
Nazir, M
Khan, MM
Khayam, SA
Li, SJ
Date : 2012
DOI : 10.1109/SafeConfig.2011.6111665
Contributors :
Related URLs :
Additional Information :

Copyright 2012 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.

Depositing User : Symplectic Elements
Date Deposited : 26 Jun 2012 11:12
Last Modified : 31 Oct 2017 14:34

Actions (login required)

View Item View Item


Downloads per month over past year

Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800