Abstract
CAPTCHA is a simple test that is designed to be easily generated by computers and easily recognized by humams, but difficult for computers to solve. It is now almost a standard security technology. The most widely deployed CAPTCHAs are text-based schemes, but to CAPTCHAs, segmenting the connected and distored characters is still an unsolving problem. In this paper, we proposed a Community Divided Model algorithm which based on complex networks to segment these CAPTCHAs. To evaluate the effectiveness of the proposed segmentation algorithm, we conducted several experiments on database which collected some CAPTCHAs from the Internet randomly. The results showed that the proposed algorithm is effective to segment two or more connected and distored characters.
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
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
von Ahn, L., Blum, M., Hopper, N.J., Langford, J.: CAPTCHA: Using Hard AI Problems for Security. In: Biham, E. (ed.) EUROCRYPT 2003. LNCS, vol. 2656, pp. 294–311. Springer, Heidelberg (2003)
Yan, J., El Ahmad, A.S.: A low-cost attack on a Microsoft CAPTCHA. In: 15th ACM Conference on Computer and Communications Security (2008)
Chellapilla, K., Larson, K., Simard, P., Czerwinski, M.: Computers beat humans at single character recognition in reading based Human Interaction Proofs (HIPs). In: 2nd Conference on Email and Anti-Spam (2005)
Simard, P.Y., Steinkraus, D., Platt, J.C.: Best Practice for Convolutional Neural Networks Applied to Visual Document Analysis. In: 7th International Conference on Document Analysis and Recognition, pp. 958–962. IEEE Computer Society, Los Alamitos (2003)
El Ahmad, A.S., Yan, J., Tayara, M.: The Robustness of Google CAPTCHAs. Bericht, Newcastle University (2011)
Mori, G., Malik, J.: Recognising objects in adversarial clutter: breaking a visual CAPTCHA. In: IEEE Conference on Computer Vision & Pattern Recognition (2003)
Chellapilla, K., Larson, K., Simard, P.Y., Czerwinski, M.: Building Segmentation Based Human-Friendly Human Interaction Proofs (HIPs). In: Baird, H.S., Lopresti, D.P. (eds.) HIP 2005. LNCS, vol. 3517, pp. 1–26. Springer, Heidelberg (2005)
Huang, S., Lee, Y., Bell, G., Ou, Z.: A projection-based segmentation algorithm for breaking MSN and YAHOO CAPTCHAs. In: Proceedings of the 2008 International Conference of Signal and Image Engineering, London, UK (2008)
Bursztein, E., Martin, M., Mitchell, C.: Text-based CAPTCHA Strengths and Weaknessses. In: 18th ACM Conference on Computer and Communications Security (2011)
Boccaletti, S., Latora, V., Moreno, Y., Chavez, M., Hwang, D.-U.: Complex networks: Structure and dynamics. Phys. Rep. 424(4-5), 175–308 (2006)
Freeman, L.C.: A set of measures of centrality based on betweenness. Sociometry 40, 35–41 (1977)
Girvan, M., Newman, M.E.J.: Community structure in social and biological networks. PNAS 99, 7821–7826 (2002)
Bursztein, E., Bethard, S., Fabry, C., Mitchell, J., Jurafsky, D.: How good are humans at solving CAPTCHAs? a large scale evaluation. In: 2010 IEEE Symposium on Security and Privacy (SP), pp. 399–413 (2010)
Authorize CAPTCHAs, https://account.authorize.net/ui/themes/anet/Welcome/ForgottenLoginID.aspx (accessed April 2012)
360buy CAPTCHAs, https://passport.360buy.com/new/registpersonal.aspx (accessed April 2012)
Tianya CAPTCHAs, http://passport.tianya.cn/register (accessed March 2012)
Windows Live CAPTCHAs, https://signup.msn.cn/register (accessed April 2012)
Taobao CAPTCHAs, http://member1.taobao.com/member/new_register.jhtml (accessed April 2012)
Zhang, T.Y., Suen, C.Y.: A fast parallel algorithm for thinning digital patterns. Communications of the ACM 27(3), 236–239 (1984)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2012 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Fang, K., Bu, Z., Xia, Z.Y. (2012). Segmentation of CAPTCHAs Based on Complex Networks. In: Lei, J., Wang, F.L., Deng, H., Miao, D. (eds) Artificial Intelligence and Computational Intelligence. AICI 2012. Lecture Notes in Computer Science(), vol 7530. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-33478-8_91
Download citation
DOI: https://doi.org/10.1007/978-3-642-33478-8_91
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-33477-1
Online ISBN: 978-3-642-33478-8
eBook Packages: Computer ScienceComputer Science (R0)